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>As for online medical articles, compliments of our Canadian friends,

Connie

> & Kistler (Hi Guys!) see " Special Problems Of Anesthesia For Little

>People " , written by Dr. Judith Hall. See URL:

>http://www.bfree.on.ca/comdir/family/lpo/INDEX.HTM#INDEX

From someone who has been under the anaesthetic a few times, my thanks for

this info are belated, but gratefully given. I've printed it off for

hopefully, NOT future reference.

However, it IS frightening what some of us have risked, out of shear

ignorance, in past operations.

Thanks again

Fred

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  • 2 years later...

> My son is going to have surgery on his arm in 2 weeks. He has

repeatedly

> dislocated it and suffered a wrestling injury with it last week. He

is 17.

> He can not have gluten, casein, milk, eggs, rice, soy, red dye. Does

anyone

> have any advice? The gluten free web sites say our kids can't have

dextrose.

> Isn't that what is in the IV?

They can use either dextrose or saline. (sugar or salt).

>Any advice would be greatly

appreciated.

Be IN the OR or right outside with the surgeon having agreed what to

do and how to do it aware you are checking up on him. These guys tend

to do what they want to once they are behind closed doors.

Get your instructions for him in the chart and have him sign off on

them. Remember to have each member of the surgical team sign off, and

review them with you.

>

> ellen V. Little

> Wellness and Marketing Consultant

> mvlittle@a...

> www.5pillars.com/813399000

> Toll Free 1-866-215-3966

> (716) 634-1771

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  • 11 months later...

I am one who NEVER has had stomach problems. Never eaten a TUMS, or

taken pepto-bismol, don't know what heartburn is... But in all 3

surgeries (c-toma, breast lump, and endometriosis - just call

me " tumor lady " ), I have had vomiting each time. Even though I tell

the anesthesiologist and I am given anti-nausea meds, I still barf

big time EVERY TIME. I absolutely hate it. I think the last

srugery, we discovered it was probably the morphine they gave me

post-op that was making me continue to throw up. I am told that I

should ask for the motion sickness patch next time. You have to

apply it at least 4 hours before surgery for it to be effective. If

someone tries this, pleaselet us know if it works.

Sandi

> Just chiming in here...I think Candy's prep for the worst/hope for

the best motto sounds about right. I had no nausea with surgeries 1

& 3, some with #2, & wicked nausea after #4. I'm sure there's a

reason, but it seems almost random.

>

> If you have a history of nausea, TELL the anesthesiologist. He (or

she) will be speaking with you before surgery, asking you questions.

Don't be shy - that's the time to let them know about nausea,

anxiety, etc., so they can adjust/be ready. They gave me anti-nausea

& anti-anxiety stuff before going into the OR, & then put anti-

nausea stuff in my IV in recovery (I'm sure they were doing it

during the op, but I was wherever one goes under anesthesia!).

>

> Yes, you do stink a bit for a couple of days. Funny smell, funny

taste. It passes.

>

> One last thing, for needle-phobics - they can give you a little

shot in the back of your hand before they insert the IV needle. It

does burn/sting for a few moments, then numbs everything so for the

IV insertion you feel nothing. If you have no trouble with IVs going

in you may not need the little shot (the nurse says she uses it

about 50% of the time) but it's an option.

>

>

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  • 1 year later...

Kathy, I had wanted epidural with " conscious sedation " and

the " amnesia drug. " As it turned out, on the advice of the

anesthesologist and for various reasons, I had the epidural and a

general anesthesia. He asked me what I was most scared of. I told

him, feeling nauseous and being sick afterwards. He said I have

three anti-nausea drugs, each one is 80% effective. I'll give you

all three. I was did not have one second of nausea! Also, as some

of you know, I am a big proponent of SmartWater and I am sure that

drinking tons of water with those electrolytes after I got home

cleared out any anesthesia " fog brain " in record time. I would say,

don't be afraid to express any fears when the anesthesologist comes

to talk to you before surgery. They don't want you to be miserable.

Except for one brief moment at the end of surgery, I don't remember

anything from the time they wheeled me out of pre-op until I got to

my room on the ortho floor.

> Hi all this is Kathy again the 38 year old scheduled for RTHR on

> April 9th. A year and a half ago I under went Laproscopic surgery

to

> remove a torn labrum while in for that they did abrasion (drilled

> holes in my hip joint to regenerate a fibro cartilage)this

procedure

> was in hopes that it would buy me 5 years before the THR. Here I am

> no time bought heading in for yet another sugery. Well my biggest

> fear is the anesthesia not from dying from it but from how sick I

> was from it the last time (wished I was dead). I read a few posts

> about the epidural approach and being awake for the surgery this

> intrigues me. First of all I am a big chicken! So the thought of

> being aware of anything makes me think I am better off with general

> anesthisia and to just deal with the sickness. Your thoughts and

> honest opinions are appreciated anyone that has undergone this

> surgery could you please share your experiences.

>

> I also want to once again thank everyone that is part of this

board.

> All of the experiences shared has greatly helped me mentally

prepare

> for this surgery. I am less frightened today that I was when I

first

> posted. Thanks! Kathy

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Many people have epidural anesthesia for hip replacement surgery.

They don't necessarily remember everything because they are also

given heavy sedation along with the epidural.

As to your concerns with nausea in conjunction with general

anesthesia, if you tell the anesthetist or anesthesiologist that

you've had a problem with that in the past you can be given medicine

that will help.

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I just had my thr on the 16th and went with an epidural with a

seditive. Trust me it's much easier!

Kenny

> > Hi all this is Kathy again the 38 year old scheduled for RTHR on

> > April 9th. A year and a half ago I under went Laproscopic surgery

> to

> > remove a torn labrum while in for that they did abrasion (drilled

> > holes in my hip joint to regenerate a fibro cartilage)this

> procedure

> > was in hopes that it would buy me 5 years before the THR. Here I am

> > no time bought heading in for yet another sugery. Well my biggest

> > fear is the anesthesia not from dying from it but from how sick I

> > was from it the last time (wished I was dead). I read a few posts

> > about the epidural approach and being awake for the surgery this

> > intrigues me. First of all I am a big chicken! So the thought of

> > being aware of anything makes me think I am better off with general

> > anesthisia and to just deal with the sickness. Your thoughts and

> > honest opinions are appreciated anyone that has undergone this

> > surgery could you please share your experiences.

> >

> > I also want to once again thank everyone that is part of this

> board.

> > All of the experiences shared has greatly helped me mentally

> prepare

> > for this surgery. I am less frightened today that I was when I

> first

> > posted. Thanks! Kathy

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Hi Kathy, I was told by my surgeon that he would definitely use the

epidural, but also said that you're not going to be totally awake, he

described it to me as more of a twilight sleep. I won't know for

sure until I go, I'm a week before you, on april 1st. I'll let you

know. - :-)

> Hi all this is Kathy again the 38 year old scheduled for RTHR on

> April 9th. A year and a half ago I under went Laproscopic surgery

to

> remove a torn labrum while in for that they did abrasion (drilled

> holes in my hip joint to regenerate a fibro cartilage)this

procedure

> was in hopes that it would buy me 5 years before the THR. Here I am

> no time bought heading in for yet another sugery. Well my biggest

> fear is the anesthesia not from dying from it but from how sick I

> was from it the last time (wished I was dead). I read a few posts

> about the epidural approach and being awake for the surgery this

> intrigues me. First of all I am a big chicken! So the thought of

> being aware of anything makes me think I am better off with general

> anesthisia and to just deal with the sickness. Your thoughts and

> honest opinions are appreciated anyone that has undergone this

> surgery could you please share your experiences.

>

> I also want to once again thank everyone that is part of this

board.

> All of the experiences shared has greatly helped me mentally

prepare

> for this surgery. I am less frightened today that I was when I

first

> posted. Thanks! Kathy

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  • 4 weeks later...
Guest guest

The ARI website has info re: anesthesia with autistic kids. We took a copy

of it to our gastroenterologist when had his gastroscopy...I don't

know if he did anything different, though. We will be praying for your

friend's daughter, their family and docs.

, mom to and

Anesthesia

> Dear list mates,

> A little of the subject matter, but I was hoping for help because I can

not

> find in archives. I remember some postings a while back regarding a

child's

> reactions to anesthesia and there was a parent that had talked to the

> anesthesiologist and come to some sort of solution. Could someone please

> advise as there is a friend of ours that needs to have their (ASD dx)

> daughter under while a brain tumor is removed. They are of course

terrified,

> but that said the one time she had anesthesia that she regressed terribly

> for several months before they could get her back. Any advise will be

> appreciated.

> Shery

>

>

>

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Guest guest

I'm not promoting this idea, but wanted to through it out to be investigated.

Lately I've been doing a lot of research on the uses of vitamin C. One of the

things I recall reading is it's supposed incredible benefit of bringing one out

quicker after being through anestisia. The DAN! doctor I am seeing for this had

been a surgeon and personally would swear by it's benefits. Thinking there must

be something to it, because if you are going to get novacane they don't want you

taking vitamin C for 24 hours prior because it will not be as effective.

Kari

Anesthesia

Dear list mates,

A little of the subject matter, but I was hoping for help because I can not

find in archives. I remember some postings a while back regarding a child's

reactions to anesthesia and there was a parent that had talked to the

anesthesiologist and come to some sort of solution. Could someone please

advise as there is a friend of ours that needs to have their (ASD dx)

daughter under while a brain tumor is removed. They are of course terrified,

but that said the one time she had anesthesia that she regressed terribly

for several months before they could get her back. Any advise will be

appreciated.

Shery

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Guest guest

People with B12 pathway problems have problems with anesthesia. Migfht be

worth checking into.

anesthesia

> Halleluia!!!

>

> Finally, I have found someone with similar problems... My son first got

his diagnosis (PDD-NOS) after having 2 surgeries a week apart. The second

one lasted about 6 hours. Last year he had surgery again to have his

tonsils removed... BINGO, another behavioral regression!!!!!

>

> I have tried to search the archives too, but have not found it. If anyone

can give me any references on this, I do appreciate it!!!

>

> Coral

>

>

>

>

>

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Guest guest

Last Nov our son was going to have tonsils and adenoids removed. We

found out anesthesia is soy based, which he is allergic to. We cancelled

the surgery. Hospital got into some hot water.

They give a lot of different meds. Are you having another surgery? I do

have some suggestions of you are.

anesthesia

Halleluia!!!

Finally, I have found someone with similar problems... My son first got

his diagnosis (PDD-NOS) after having 2 surgeries a week apart. The

second one lasted about 6 hours. Last year he had surgery again to have

his tonsils removed... BINGO, another behavioral regression!!!!!

I have tried to search the archives too, but have not found it. If

anyone can give me any references on this, I do appreciate it!!!

Coral

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Guest guest

They are wanting to set up another one-so would love some suggestions for

them!

anesthesia

Halleluia!!!

Finally, I have found someone with similar problems... My son first got his

diagnosis (PDD-NOS) after having 2 surgeries a week apart. The second one

lasted about 6 hours. Last year he had surgery again to have his tonsils

removed... BINGO, another behavioral regression!!!!!

I have tried to search the archives too, but have not found it. If anyone

can give me any references on this, I do appreciate it!!!

Coral

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Guest guest

What kind of surgery are we talking about?

Suggestions:

1st- Set up an appointment with the anesthesiologist ASAP. Get your

doctor on board with whatever allergies and complications exist. Have

him send a letter to the " group " or a specific anesthesiologist if you

can get one.

2nd- Have the surgery done at a childrens hospital that deals with

complicated issues.

3rd- Becareful of Tylenol. What they use has dye in it. Find out if you

can get a substitute. They were crabby with me on this one- the rest

tend to thin the blood.

4th- Get the records of what meds were administered in the other

surgery's and REQUIRE the doc to review the file and find replacements

for meds that might have caused a reaction. - Of coarse, make sure you

document/remember the reactions that happened before.

5th- Call the hospital pharmacy and tell them you need the formulation

(containing

everything in the stuff) of all the materials the doctor listed plus all

the

iv vehicles.

6th- Check on the bags that hold meds for surgery. Sounds strange, but

its actually well documented how they leach chemicals. The pharmacist

was well aware of this issue when I asked, and he said they had replaced

them with a new vendor- and newly designed bags. Hospitals used to use

glass only.

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Guest guest

Hello ,

Not all anaesthetic agents are soy based.

Were you meaning propofol?

Usually it can be substituted with another when there is a problem if

allergies/sensitivities are indicated.

Sorry you had to cancel.

Regards,

Joe

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Guest guest

Yes, I believe that was the one. I probably sounded as if I was

generalizing to all agents... That tends to happen to me on the net.. ;)

I basically have no trust in medical professionals and triple check

everything they do now. In our case, my son had a skin prick allergy to

soy, so I cant imagine what they could have done to him. I shudder to

think.... Now, I think if I had to have surgery for him, I would demand

an anestesiologist that had a speciality for complications (even though

he has never had a problem because he has never had surgery). I would be

in the funny farm if they screwed him up again.

Their general attitude toward me was laughable- like I shouldn't

question the meds they were giving, shouldn't ask for the ingredients,

or double check the procedure. In the end, I didn't make a stink about

the huge mistake they 'almost made'. The guy wouldn't even give me a

definative list of meds - he said any doc might do the surgery depending

on the rotation, and they all have their own 'recipes'. When I

discovered it on the internet after demanding all the names of meds they

" might use " - (as he would not provide me a list from the pharmacy) - I

cancelled the surgery (the day before). This guy was so stupid, he

called and left a message on my machine saying " Don't worry, I checked

with the pharmacy and all the ingredients you say he's reactive to arent

there " . It was pathetic incompetance.

I guess I havent gotten over it yet. :)

RE: anesthesia

Hello ,

Not all anaesthetic agents are soy based.

Were you meaning propofol?

Usually it can be substituted with another when there is a problem if

allergies/sensitivities are indicated.

Sorry you had to cancel.

Regards,

Joe

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  • 5 months later...

i am a nurse anesthetist and I found this article on the internet. My

child is on the spectrum and we are going to have MTHFR testing done.

Currently I am taking folic acid for a high homocystine level( MTHFR

defect). I have heard that they think this gene has something to do

with folate metabolism which our kids need for metal metabolism. I

have been practicing for over 20 years and when we put kids to sleep we

use high flows of nitrous. Last year I started getting numbness in my

face and arms. I had a cat scan and they found nothing wrong. But

then I discovered I got the numbness after I did a room full of kids

that day. Still trying to figure that one out but I am now trying not

to do as many kids if possible. Pass this to your anesthesia

friend....Sym

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Volume 349:45-50

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July 3, 2003

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Number 1

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Adverse Effect of Nitrous Oxide in a Child with

5,10-Methylenetetrahydrofolate Reductase Deficiency

R. Selzer, Ph.D., S. Rosenblatt, M.D., Renata Laxova,

M.D., and Kirk Hogan, M.D., J.D.

 

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PubMed Citation

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Nitrous oxide irreversibly oxidizes the cobalt atom of vitamin B12,

thereby inhibiting the activity of the cobalamin-dependent enzyme

methionine synthase (or 5-methyltetrahydrofolate–homocysteine

S-methyltransferase; Enzyme Commission code EC 2.1.1.13). Methionine

synthase catalyzes the remethylation of 5-methyltetrahydrofolate and

homocysteine to tetrahydrofolate and methionine (Figure 1). Methionine,

by way of its activated form, S-adenosylmethionine, is the principal

substrate for methylation in many biochemical reactions, including

assembly of the myelin sheath, methyl substitutions in

neurotransmitters, and DNA synthesis in rapidly proliferating tissues.1

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Figure 1. The Folate and Homocysteine Metabolic Cycles and the

Enzymatic Site of Nitrous Oxide Toxicity.

Co denotes cobalt.

 

We report the neurologic deterioration and death of a child

anesthetized twice with nitrous oxide before the diagnosis of

5,10-methylenetetrahydrofolate reductase (MTHFR; EC 1.5.1.20)

deficiency (Online Mendelian Inheritance in Man number 236250) was

established.2 MTHFR catalyzes the synthesis of

5-methyltetrahydrofolate. Sequence analysis of RNA transcripts and

genomic DNA from the patient and his family members, together with

direct assays of MTHFR activity in fibroblasts, revealed that the

enzyme deficiency was caused by a novel MTHFR mutation (1755G

----------

A), which changes the conserved methionine at position 581 of the

enzyme to isoleucine; this mutation is coinherited with two other,

common MTHFR polymorphisms (677C

----------

T and 1298A

----------

C), each of which is associated with depressed enzyme function.3,4 We

propose that a nitrous oxide–induced defect of methionine synthase

superimposed on an inherited defect of MTHFR caused the patient's

death.

Case Report

Details of the patient's clinical course and biochemical and

pathological findings were reported by Beckman et al. in 1987.2 In

brief, the child appeared normal until three months of age, when a mass

in the left leg was noted. It was not known before the patient's

surgery that his father and one of his uncles had serum levels of total

homocysteine above 20.0 µmol per liter and above 30.0 µmol per liter,

respectively (normal range, 5.4 to 13.9). The proband's sibling, who

was receiving lifelong therapy with high-dose vitamin B supplements,

had a homocysteine level of 4.3 µmol per liter. Neither the father nor

the sibling had received nitrous oxide. On preoperative assessment for

excisional biopsy of the mass, the patient's physical status was deemed

class I according to the American Society of Anesthesiologists criteria

(class I denotes good health and class V critical illness). After

premedication with atropine and induction of anesthesia with sodium

thiopental and succinylcholine, the child's trachea was intubated;

anesthesia was maintained with 0.75 percent halothane and 60 percent

nitrous oxide in oxygen for 45 minutes.

The surgical biopsy revealed an infantile fibrosarcoma, and resection

of the mass was performed on the fourth day after the biopsy. After

induction of anesthesia with halothane, the child was anesthetized for

270 minutes with 0.75 percent halothane and 60 percent nitrous oxide.

At the conclusion of the operation, his trachea was extubated, and he

was transferred while awake to the intensive care unit. He was

discharged on the seventh postoperative day in apparently good health.

Seventeen days later (25 days after the resection), the patient was

admitted because of seizures and episodes of apnea. On examination, the

infant was severely hypotonic, without reflexes and with ataxic

ventilation. Cranial computed tomography showed generalized atrophy of

the brain, with enlarged prepontine and medullary cisterns. The urine

was positive for homocystine (1.30 µmol per milligram of creatinine

[normal value, 0]) but negative for organic acids and methylmalonic

acid. The plasma homocystine level was elevated, at 0.6 mg per

deciliter (normal value, <0.01), and the methionine level was low, at

0.06 mg per deciliter (normal mean [±SD] value, 0.48±0.18); the vitamin

B12 level was normal, at 403 pg per milliliter (297 pmol per liter)

(normal range, 150 to 800 pg per milliliter [111 to 590 pmol per

liter]). The serum folate level, measured by radioimmunoassay, was 3.8

ng per milliliter (8.5 nmol per liter) (normal range, 2.5 to 15.0 ng

per milliliter [5.6 to 33.4 nmol per liter]), and the level of folate

in the cerebrospinal fluid was 26.0 ng per milliliter (57.9 nmol per

liter) (normal range, 10.6 to 85.0 ng per milliliter [23.6 to 189.2

nmol per liter]).

The patient died at 130 days of age (46 days after the resection)

after a respiratory arrest. An autopsy showed asymmetric cerebral

atrophy and severe demyelination, with astrogliosis and

oligodendroglial-c ell depletion in the midbrain, medulla, and

cerebellum. The values for MTHFR activity in cultured fibroblasts

reported post mortem were 1.22 and 0.8 nmol of formaldehyde produced

per milligram of protein per hour (normal mean value, 5.04±1.36) with

and without flavinadenine dinucleotide, respectively. The simultaneous

control values were 6.4 and 5.4 nmol of formaldehyde produced per hour

per milligram of protein with and without flavinadenine dinucleotide,

respectively.5

Methods

The investigations were carried out with approval of the University of

Wisconsin's institutional review board. Written informed consent was

obtained from all the participants.

Fibroblast Culture and MTHFR Activity

Fibroblasts were cultured from skin-punch biopsy specimens obtained

from both parents and from the patient's stored samples. MTHFR activity

was measured at confluence, as previously described.6 All the assays

were performed in duplicate, with simultaneous assay of a normal

control.

Preparation and Sequence Analysis of Genomic DNA

Genomic DNA was isolated from the cultured fibroblasts from the

patient and both parents and from either blood or buccal cells from

other relatives. Each of the 11 MTHFR exons was amplified from genomic

DNA by the polymerase chain reaction (PCR) with the use of newly

designed intronic primers.7,8 (The sequences of the primers are listed

in Supplementary Appendix 1 with the full text of this article at

http://www.nejm.org.) The patient's and both parents' PCR products were

bidirectionally sequenced. A novel mutation in the patient's DNA at

nucleotide 1755 (exon 10) and two previously described frequent

polymorphisms at positions 677 (exon 4) and 1298 (exon 7) in the MTHFR

gene were analyzed in the genomic DNA from the parents and other

relatives with the use of the restriction enzymes NlaIII, HinfI, and

MboII, as previously described.3,4 Family members were also screened as

previously described for common polymorphisms in the genes encoding

enzymes that regulate folate and homocysteine metabolism; these

polymorphisms have been implicated in the pathogenesis of neural-tube

defects, other congenital anomalies, and cardiovascular and neoplastic

disease.9 The polymorphisms include those that encode methionine

synthase (MTR; the polymorphism results in the substitution of glycine

for aspartic acid at residue 919),10 methionine synthase reductase

(MTRR; the polymorphism results in the substitution of methionine for

isoleucine at residue 22),11 and cystathionine

----------

-synthase (CBS; the polymorphism is a 68-bp duplication).12

RNA Analysis

To evaluate the expression of an intact copy of the predominant 7.2-kb

MTHFR isoform,13 RNA was isolated from the patient's cultured

fibroblasts. A 2206-bp product containing the entire coding region was

amplified by PCR from the complementary DNA (cDNA) transcript and

sequenced in full. The 7.2-kb cDNA product was amplified as seven

overlapping fragments ranging from 1.0 to 2.2 kb in size, as verified

by gel electrophoresis. (The primers used to sequence the cDNA

transcript and to amplify the cDNA as overlapping fragments are listed

in Supplementary Appendixes 2 and 3, respectively, with the full text

of this article at http://www.nejm.org.) Bands corresponding to the

expected fragment sizes were excised, and the first 300 bases of the 5'

and 3' ends were sequenced to allow positive identification of each

fragment. Fragments from the patient and an unrelated control were then

compared.

Results

Enzyme Activity in Fibroblasts

The patient's MTHFR activity in two replicates was 0.76 and 0.03 nmol

of formaldehyde per milligram of protein per hour (normal mean value,

13.3±4.6 with the use of the current method of measurement6), with a

simultaneous normal control of 11.52 nmol of formaldehyde per milligram

of protein per hour. MTHFR activity in the father and mother (1.8 and

6.1 nmol of formaldehyde per milligram of protein per hour,

respectively) was reduced, with a control level of 9.5 nmol of

formaldehyde per milligram of protein per hour.

Genomic DNA-Sequence Analysis

The patient was found to be heterozygous for a novel mutation, 1755G

----------

A in exon 10, which causes a substitution of isoleucine for methionine

at residue 581 (M581I)14 (GenBank accession number, NM_005957).

Restriction-enzyme analysis confirmed the presence of the 1755G

----------

A mutation in the heterozygous patient, his father, his brother, one

uncle, and one aunt, but not in 100 control chromosomes. The patient

was also heterozygous for a 677C

----------

T mutation in exon 4 (resulting in a substitution of valine for alanine

at residue 222) and a 1298A

----------

C mutation in exon 7 (resulting in a substitution of alanine for

glutamic acid at residue 429). In addition to being heterozygous for

1755G

----------

A, the father was homozygous (TT) for the 677C

----------

T mutation and homozygous (AA) at 1298A (Figure 2). The mother was

heterozygous for both common polymorphisms and homozygous (wild type)

at 1755G. The sibling's haplotype was identical to that of the patient

in all coding regions. The novel mutation at 1755G

----------

A was therefore transmitted to the patient from a paternal chromosome,

in cis configuration with the 677C

----------

T mutation. Two of the father's four siblings had haplotypes identical

to the father's haplotype and were heterozygous for the 1755G

----------

A mutation and homozygous for the 677C

----------

T mutation (Table 1).

----------

View larger version (6K):

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Figure 2. Nucleotide Changes in the MTHFR Gene in the Patient and His

Parents.

In addition to the coding changes, the patient (the proband) and his

mother were heterozygous for a substitution of adenine for cysteine at

position 2355, which is 375 bases (in the 3' direction) from the stop

codon, on the same chromosome as the 1298C polymorphism. This

substitution is in a region of unknown importance. Asterisks denote

DNA-sequence variants. The open bars represent the MTHFR gene, and the

black bars the remainder of each chromosome in the pair.

 

View this table:

[in this window]

[in a new window]

 

Table 1. Polymorphisms in the Patient and Members of His Family.

 

We sequenced 25 to 40 bases beyond all intronic boundaries to look for

altered splice junctions. There were no substitutions in the 5' and 3'

untranslated regions flanking the MTHFR gene, within or proximate to a

putative binding site for a transcription factor or an actual start

site mapped by Gaughan et al.13 and Homberger et al.15 The DNA sequence

approximately 550 bp in the 3' direction from the MTHFR stop codon and

a 400-bp segment encompassing the distal 3'-polyadenylation site

contained several polymorphisms, but none at sites with recognized

functional significance.

We also performed genomic analysis of the genes encoding methionine

synthase, methionine synthase reductase, and cystathionine

----------

-synthase. Genotypes at these loci for all members of the pedigree are

provided in Table 1.

RNA Analysis

No size differences were observed among the seven MTHFR cDNA

fragments, indicating that the patient's fibroblasts expressed an

intact MTHFR transcript. The 2.2-kb product contained the entire coding

region of the transcript and was used to sequence a region beginning 50

bp in the 5' direction from the translational start site and ending 150

bp downstream of the stop codon. This product was of the expected

length, and no alternate splicing variants were detected. The entire

product was sequenced and compared with the published sequence14

(GenBank accession number, NM_005957). The presence of the heterozygous

common polymorphisms 677C

----------

T and 1298A

----------

C, as well as the heterozygote substitution 1775G

----------

A, was confirmed.

Discussion

The inactivation of methionine synthase by nitrous oxide has been

demonstrated with purified enzyme,16 in cultured cells,17,18 in animal

models,19 and in humans.20,21,22 The mean half-time of inactivation is

46 minutes. Residual methionine synthase activity more than 200 minutes

after the start of nitrous oxide administration approaches zero.21

Mice, pigs, and rats exposed to nitrous oxide have delayed recovery of

enzyme activity for periods of four days or more.19,23,24,25 Recovery

in cultured cells indicates that nitrous oxide–mediated inhibition is

irreversible, with de novo synthesis of the enzyme required to restore

activity.26

The untoward consequences of nitrous oxide anesthesia in our patient

are reminiscent of two recent case reports. In the first, an

eight-month-old child had acute neurologic deterioration six days after

an 80-minute period of anesthesia with nitrous oxide.27 In the second,

a four-month-old child was admitted because of hypotonia, dehydration,

and acidosis three weeks after surgery that had involved a 180-minute

period of anesthesia with nitrous oxide.28 Both children were found to

have severe dietary cobalamin deficiency. These instances of methionine

synthase inhibition have a time course and clinical features similar to

those observed in our patient but were nonlethal, perhaps because they

were elicited after only a single exposure to nitrous oxide. Moreover,

our patient had an inborn error of metabolism in an essential precursor

in a metabolic pathway, rather than an acquired deficiency, and nitrous

oxide was delivered on two occasions only a few days apart.

Severe MTHFR deficiency is an autosomal recessive disorder

characterized by progressive hypotonia, convulsions, and psychomotor

retardation. The clinical presentation may be subtle, with the disorder

manifested as developmental disability in the setting of moderate

homocystinuria and hyperhomocysteinemia and low-to-normal levels of

plasma methionine.29 Twenty-nine mutations in MTHFR are associated with

severe deficiency, with a resulting activity level that is usually 0 to

30 percent of control activity.7,8,14,30,31,32,33 Most patients are

heterozygous for multiple MTHFR substitutions; a small minority are

homozygous for mutations at this locus. The 1755G

----------

A substitution identified in our patient occurs in a phylogenetically

conserved region of the MTHFR protein (as assessed with BLASTP

software, version 2.2.1). This region, which is thought to be essential

for functional protein folding,34 is a " hot spot " for mutations leading

to MTHFR deficiency (1711C

----------

T, 1727C

----------

T, 1762A

----------

T, and 1768G

----------

A).7,8 The heterozygous presence of the 1755G

----------

A substitution in the patient's father, brother, one uncle, and one

aunt and its absence in 100 independent control chromosomes suggest

that it is not a benign variant.

Compound heterozygosity for the common MTHFR alleles 677C

----------

T and 1298A

----------

C, as seen in the patient, his mother, and his brother, causes

elevations in the plasma homocysteine level4 that are associated with a

50 to 60 percent decrement in enzyme activity.35 In the absence of

coding mutations elsewhere in the MTHFR gene or evidence of a mutant

splice variant, our patient's deficient enzyme activity may be

attributable to compound heterozygosity for the novel 1755G

----------

A mutation, with the prevalent 677C

----------

T polymorphism on the same (paternal) chromosome and the 1298A

----------

C mutation on the maternal chromosome. It has recently been shown that

when mutations causing severe MTHFR deficiency are expressed in cis

configuration with the common 677C

----------

T variant, the resultant phenotype is markedly aggravated.34

Every year, approximately 45 million persons in North America undergo

anesthesia, and nitrous oxide constitutes a major component in about

half these procedures.36 Because of the growing use of nitrous

oxide,37,38,39,40,41 patients with known mutations associated with mild

or severe abnormalities in folate-cycle enzymes are increasingly likely

to receive nitrous oxide. On the strength of the current findings, we

believe that patients with a diagnosis of severe MTHFR deficiency

should not receive nitrous oxide as anesthesia. In the case of

emergency procedures, patients whose clinical presentation fits that of

severe MTHFR deficiency, even if the disorder has not been diagnosed,

should also not receive nitrous oxide. In the case of elective

procedures, patients whose clinical presentation fits that of severe

MTHFR deficiency should be evaluated, and the diagnosis should be ruled

out before anesthesia with nitrous oxide is contemplated.

Supported by grants from the Doris Duke Foundation and the University

of Wisconsin Department of Anesthesiology Research and Development Fund

(to Dr. Hogan) and the Canadian Institutes of Health Research (to Dr.

Rosenblatt).

We are indebted to Singh Sekhon, Ph.D. (University of Wisconsin,

Madison), for the fibroblast cultures and to H. , M.D.

(Metabolite Laboratories, Denver), for the assays of total

homocysteine.

Source Information

From the Departments of Anesthesiology (R.R.S., K.H.) and Medical

Genetics (R.L.), University of Wisconsin Medical School, Madison; and

the Departments of Human Genetics, Medicine, Pediatrics, and Biology,

McGill University, Montreal (D.S.R.).

Address reprint requests to Dr. Hogan at the Department of

Anesthesiology, B6/319 Clinical Sciences Center, 600 Highland Ave.,

Madison, WI 53792, or at khogan@....

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methylation. FASEB J 1996;10:471-480.[Abstract]

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findings in 5,10-methylene tetrahydrofolate reductase deficiency. Birth

Defects Orig Artic Ser 1987;23:47-64.[Medline]

3. Frosst P, Blom HJ, Milos R, et al. A candidate genetic risk

factor for vascular disease: a common mutation in

methylenetetrahydrofolate reductase. Nat Genet

1995;10:111-113.[iSI][Medline]

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mutation in the methylenetetrahydrofolate reductase gene: an additional

risk factor for neural-tube defects? Am J Hum Genet

1998;62:1044-1051.[CrossRef][iSI][Medline]

5. Kanwar YS, Manaligod JR, Wong PW. Morphologic studies in a

patient with homocystinuria due to 5,10-methylenetetrahydrofolate

reductase deficiency. Pediatr Res 1976;10:598-609.[Abstract]

6. Rosenblatt DS, Erbe RW. Methylenetetrahydrofolate reductase in

cultured human cells. I. Growth and metabolic studies. Pediatr Res

1977;11:1137-1141.[iSI][Medline]

7. Sibani S, Christensen B, O'Ferrall E, et al. Characterization of

six novel mutations in the methylenetetrahydrofolate reductase (MTHFR)

gene in patients with homocystinuria. Hum Mutat

2000;15:280-287.[CrossRef][iSI][Medline]

8. Kluijtmans LA, Wendel U, s EM, van den Heuvel LP, Trijbels

FJ, Blom HJ. Identification of four novel mutations in severe

methylenetetrahydrofolate reductase deficiency. Eur J Hum Genet

1998;6:257-265.[CrossRef][iSI][Medline]

9. Schwahn B, Rozen R. Polymorphisms in the

methylenetetrahydrofolate reductase gene: clinical consequences. Am J

Pharmacogenomics 2001;1:189-201.

10. Harmon DL, Shields DC, Woodside JV, et al. Methionine synthase

D919G polymorphism is a significant but modest determinant of

circulating homocysteine concentrations. Genet Epidemiol

1999;17:298-309.[CrossRef][iSI][Medline]

11. A, Platt R, Wu Q, et al. A common variant in methionine

synthase reductase combined with low cobalamin (vitamin B12) increases

risk for spina bifida. Mol Genet Metab

1999;67:317-323.[CrossRef][iSI][Medline]

12. Tsai MY, Bignell M, Schwichtenberg K, Hanson NQ. High

prevalence of a mutation in the cystathionine beta-synthase gene. Am J

Hum Genet 1996;59:1262-1267.[iSI][Medline]

13. Gaughan DJ, Barbaux S, Kluijtmans LA, Whitehead AS. The human

and mouse methylenetetrahydrofolate reductase (MTHFR) genes: genomic

organization, mRNA structure and linkage to the CLCN6 gene. Gene

2000;257:279-289.[CrossRef][iSI][Medline]

14. Goyette P, Sumner JS, Milos R, et al. Human

methylenetetrahydrofolate reductase: isolation of cDNA mapping and

mutation identification. Nat Genet 1994;7:551-551.

15. Homberger A, Linnebank M, Winter C, et al. Genomic structure

and transcript variants of the human methylenetetrahydrofolate

reductase gene. Eur J Hum Genet 2000;8:725-729.[CrossRef][iSI][Medline]

16. Frasca V, Riazzi BS, s RG. In vitro inactivation of

methionine synthase by nitrous oxide. J Biol Chem

1986;261:15823-15826.[Abstract/Full Text]

17. Christensen B, Rosenblatt DS, Chu RC, Ueland PM. Effect of

methionine and nitrous oxide on homocysteine export and remethylation

in fibroblasts from cystathionine synthase-deficient, cblG, and cblE

patients. Pediatr Res 1994;35:3-9.[Abstract]

18. Fiskerstrand T, Ueland PM, Refsum H. Folate depletion induced

by methotrexate affects methionine synthase activity and its

susceptibility to inactivation by nitrous oxide. J Pharmacol Exp Ther

1997;282:1305-1311.[Abstract/Full Text]

19. Kondo H, Osborne ML, Kolhouse JF, et al. Nitrous oxide has

multiple deleterious effects on cobalamin metabolism and causes

decreases in activities of both mammalian cobalamin-dependent enzymes

in rats. J Clin Invest 1981;67:1270-1283.[iSI][Medline]

20. Koblin DD, Waskell L, JE, Stokstad EL, Eger EI II.

Nitrous oxide inactivates methionine synthetase in human liver. Anesth

Analg 1982;61:75-78.[Abstract]

21. Royston BD, Nunn JF, Weinbren HK, Royston D, Cormack RS. Rate

of inactivation of human and rodent hepatic methionine synthase by

nitrous oxide. Anesthesiology 1988;68:213-216.[iSI][Medline]

22. Christensen B, Guttormsen AB, Schneede J, et al. Preoperative

methionine loading enhances restoration of the cobalamin-dependent

enzyme methionine synthase after nitrous oxide anesthesia.

Anesthesiology 1994;80:1046-1056.[iSI][Medline]

23. Deacon R, Lumb M, J, et al. Inactivation of methionine

synthase by nitrous oxide. Eur J Biochem 1980;104:419-423.[Abstract]

24. Molloy AM, Orsi B, Kennedy DG, Kennedy S, Weir DG, JM.

The relationship between the activity of methionine synthase and the

ratio of S-adenosylmethionine to S-adenosylhomocysteine in the brain

and other tissues of the pig. Biochem Pharmacol

1992;44:1349-1355.[CrossRef][iSI][Medline]

25. Koblin DD, JE, Deady JE, Stokstad EL, Eger EI II.

Inactivation of methionine synthetase by nitrous oxide in mice.

Anesthesiology 1981;54:318-324.[iSI][Medline]

26. Riedel B, Fiskerstrand T, Refsum H, Ueland PM. Co-ordinate

variations in methylmalonyl-CoA mutase and methionine synthase, and the

cobalamin cofactors in human glioma cells during nitrous oxide exposure

and the subsequent recovery phase. Biochem J

1999;341:133-138.[CrossRef][iSI][Medline]

27. Felmet K, Robins B, Tilford D, Hayflick SJ. Acute neurologic

decompensation in an infant with cobalamin deficiency exposed to

nitrous oxide. J Pediatr 2000;137:427-428.[CrossRef][iSI][Medline]

28. McNeely JK, Buczulinski B, Rosner DR. Severe neurological

impairment in an infant after nitrous oxide anesthesia. Anesthesiology

2000;93:1549-1550.[iSI][Medline]

29. Rosenblatt DS, Fenton WA. Inherited disorders of folate and

cobalamin transport and metabolism. In: Scriber CR, Beaudet AL, Sly WS,

Valle D, eds. The metabolic & molecular bases of inherited disease. 8th

ed. Vol. 3. New York: McGraw-Hill, 2001:3897-933.

30. Goyette P, Christensen B, Rosenblatt DS, Rozen R. Severe and

mild mutations in cis for the methyelentetrahydrofolate reductase

(MTHFR) gene, and description of five novel mutations in MTHFR. Am J

Hum Genet 1996;59:1268-1275.[iSI][Medline]

31. Goyette P, Frosst P, Rosenblatt DS, Rozen R. Seven novel

mutations in the methylenetetrahydrofolate reductase gene and

genotype/phenotype correlations in severe methylenetetrahydrofolate

reductase deficiency. Am J Hum Genet 1995;56:1052-1059.[iSI][Medline]

32. Tonetti C, Amiel J, Munnich A, Zittoun J. Impact of new

mutations in the methylenetetrahydrofolate reductase gene assessed on

biochemical phenotypes: a familial study. J Inherit Metab Dis

2001;24:833-842.[CrossRef][iSI][Medline]

33. Homberger A, Linnebank M, Sewell A, Suormala T, Fowler B, Koch

HG. Severe methylenetetrahydrofolate reductase deficiency: two novel

genotypes with different clinical course. J Inherit Metab Dis

2001;24:Suppl 1:50-50. abstract.

34. Goyette P, Rozen R. The thermolabile variant 677C

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T can further reduce activity when expressed in cis with severe

mutations for human methylenetetrahydrofolate reductase. Hum Mutat

2000;16:132-138.[iSI][Medline]

35. Weisberg I, Tran P, Christensen B, Sibani S, Rozen R. A second

genetic polymorphism in methylenetetrahydrofolate reductase (MTHFR)

associated with decreased enzyme activity. Mol Genet Metab

1998;64:169-172.[CrossRef][iSI][Medline]

36. Orkin FK, SJ. Scope of modern anesthetic practice. In:

RD, ed. Anesthesia. 5th ed. Vol. 2. Philadelphia: Churchill

Livingstone, 2000:2577-85.

37. Peretz B, Katz J, Zilburg I, Shemer J. Response to

nitrous-oxide and oxygen among dental phobic patients. Int Dent J

1998;48:17-23.[iSI][Medline]

38. Keating HJ III, Kundrat M. Patient-controlled analgesia with

nitrous oxide in cancer pain. J Pain Symptom Manage

1996;11:126-130.[CrossRef][iSI][Medline]

39. Luhmann JD, Kennedy RM, Porter FL, JP, Jaffe DM. A

randomized clinical trial of continuous-flow nitrous oxide and

midazolam for sedation of young children during laceration repair. Ann

Emerg Med 2001;37:20-27.[CrossRef][iSI][Medline]

40. Castera L, Negre I, Samii K, Buffet C. Patient-administered

nitrous oxide/oxygen inhalation provides safe and effective analgesia

for percutaneous liver biopsy: a randomized placebo-controlled trial.

Am J Gastroenterol 2001;96:1553-1557.[CrossRef][iSI][Medline]

41. Krauss B. Continuous-flow nitrous oxide: searching for the

ideal procedural anxiolytic for toddlers. Ann Emerg Med

2001;37:61-62.[CrossRef][iSI][Medline]

 

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Nitrous Oxide and 5,10-Methylenetetrahydrofolate Reductase

Burman J. F., Kaufman J. L., Hogan K., Erbe R. W.

Extract | Full Text | PDF  

N Engl J Med 2003; 349:1479-1480, Oct 9, 2003. Correspondence

This article has been cited by other articles:

• (2003). Lucina. Arch. Dis. Child. 88: 1142-1142 [Full Text]  

• (2003). Fatal Combination: Nitrous Oxide Anesthesia and Methionine

Pathway Defects. Journal Watch Neurology 2003: 5-5 [Full Text]  

• Burman, J. F., Kaufman, J. L., Hogan, K., Erbe, R. W. (2003).

Nitrous Oxide and 5,10-Methylenetetrahydrofolate Reductase. N Engl J

Med 349: 1479-1480 [Full Text]  

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Pardon me for asking, but if your experiencing these symptoms from the

possibility of nitrous and putting kids to sleep ..... what effect does that

have on the children?

That kind of scares me.

Shauna

[ ] Re: anesthesia

i am a nurse anesthetist and I found this article on the internet. My

child is on the spectrum and we are going to have MTHFR testing done.

Currently I am taking folic acid for a high homocystine level( MTHFR

defect). I have heard that they think this gene has something to do

with folate metabolism which our kids need for metal metabolism. I

have been practicing for over 20 years and when we put kids to sleep we

use high flows of nitrous. Last year I started getting numbness in my

face and arms. I had a cat scan and they found nothing wrong. But

then I discovered I got the numbness after I did a room full of kids

that day. Still trying to figure that one out but I am now trying not

to do as many kids if possible. Pass this to your anesthesia

friend....Sym

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Adverse Effect of Nitrous Oxide in a Child with

5,10-Methylenetetrahydrofolate Reductase Deficiency

R. Selzer, Ph.D., S. Rosenblatt, M.D., Renata Laxova,

M.D., and Kirk Hogan, M.D., J.D.

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Nitrous oxide irreversibly oxidizes the cobalt atom of vitamin B12,

thereby inhibiting the activity of the cobalamin-dependent enzyme

methionine synthase (or 5-methyltetrahydrofolate-homocysteine

S-methyltransferase; Enzyme Commission code EC 2.1.1.13). Methionine

synthase catalyzes the remethylation of 5-methyltetrahydrofolate and

homocysteine to tetrahydrofolate and methionine (Figure 1). Methionine,

by way of its activated form, S-adenosylmethionine, is the principal

substrate for methylation in many biochemical reactions, including

assembly of the myelin sheath, methyl substitutions in

neurotransmitters, and DNA synthesis in rapidly proliferating tissues.1

----------

View larger version (13K):

[in this window]

[in a new window]

Figure 1. The Folate and Homocysteine Metabolic Cycles and the

Enzymatic Site of Nitrous Oxide Toxicity.

Co denotes cobalt.

We report the neurologic deterioration and death of a child

anesthetized twice with nitrous oxide before the diagnosis of

5,10-methylenetetrahydrofolate reductase (MTHFR; EC 1.5.1.20)

deficiency (Online Mendelian Inheritance in Man number 236250) was

established.2 MTHFR catalyzes the synthesis of

5-methyltetrahydrofolate. Sequence analysis of RNA transcripts and

genomic DNA from the patient and his family members, together with

direct assays of MTHFR activity in fibroblasts, revealed that the

enzyme deficiency was caused by a novel MTHFR mutation (1755G

----------

A), which changes the conserved methionine at position 581 of the

enzyme to isoleucine; this mutation is coinherited with two other,

common MTHFR polymorphisms (677C

----------

T and 1298A

----------

C), each of which is associated with depressed enzyme function.3,4 We

propose that a nitrous oxide-induced defect of methionine synthase

superimposed on an inherited defect of MTHFR caused the patient's

death.

Case Report

Details of the patient's clinical course and biochemical and

pathological findings were reported by Beckman et al. in 1987.2 In

brief, the child appeared normal until three months of age, when a mass

in the left leg was noted. It was not known before the patient's

surgery that his father and one of his uncles had serum levels of total

homocysteine above 20.0 µmol per liter and above 30.0 µmol per liter,

respectively (normal range, 5.4 to 13.9). The proband's sibling, who

was receiving lifelong therapy with high-dose vitamin B supplements,

had a homocysteine level of 4.3 µmol per liter. Neither the father nor

the sibling had received nitrous oxide. On preoperative assessment for

excisional biopsy of the mass, the patient's physical status was deemed

class I according to the American Society of Anesthesiologists criteria

(class I denotes good health and class V critical illness). After

premedication with atropine and induction of anesthesia with sodium

thiopental and succinylcholine, the child's trachea was intubated;

anesthesia was maintained with 0.75 percent halothane and 60 percent

nitrous oxide in oxygen for 45 minutes.

The surgical biopsy revealed an infantile fibrosarcoma, and resection

of the mass was performed on the fourth day after the biopsy. After

induction of anesthesia with halothane, the child was anesthetized for

270 minutes with 0.75 percent halothane and 60 percent nitrous oxide.

At the conclusion of the operation, his trachea was extubated, and he

was transferred while awake to the intensive care unit. He was

discharged on the seventh postoperative day in apparently good health.

Seventeen days later (25 days after the resection), the patient was

admitted because of seizures and episodes of apnea. On examination, the

infant was severely hypotonic, without reflexes and with ataxic

ventilation. Cranial computed tomography showed generalized atrophy of

the brain, with enlarged prepontine and medullary cisterns. The urine

was positive for homocystine (1.30 µmol per milligram of creatinine

[normal value, 0]) but negative for organic acids and methylmalonic

acid. The plasma homocystine level was elevated, at 0.6 mg per

deciliter (normal value, <0.01), and the methionine level was low, at

0.06 mg per deciliter (normal mean [±SD] value, 0.48±0.18); the vitamin

B12 level was normal, at 403 pg per milliliter (297 pmol per liter)

(normal range, 150 to 800 pg per milliliter [111 to 590 pmol per

liter]). The serum folate level, measured by radioimmunoassay, was 3.8

ng per milliliter (8.5 nmol per liter) (normal range, 2.5 to 15.0 ng

per milliliter [5.6 to 33.4 nmol per liter]), and the level of folate

in the cerebrospinal fluid was 26.0 ng per milliliter (57.9 nmol per

liter) (normal range, 10.6 to 85.0 ng per milliliter [23.6 to 189.2

nmol per liter]).

The patient died at 130 days of age (46 days after the resection)

after a respiratory arrest. An autopsy showed asymmetric cerebral

atrophy and severe demyelination, with astrogliosis and

oligodendroglial-c ell depletion in the midbrain, medulla, and

cerebellum. The values for MTHFR activity in cultured fibroblasts

reported post mortem were 1.22 and 0.8 nmol of formaldehyde produced

per milligram of protein per hour (normal mean value, 5.04±1.36) with

and without flavinadenine dinucleotide, respectively. The simultaneous

control values were 6.4 and 5.4 nmol of formaldehyde produced per hour

per milligram of protein with and without flavinadenine dinucleotide,

respectively.5

Methods

The investigations were carried out with approval of the University of

Wisconsin's institutional review board. Written informed consent was

obtained from all the participants.

Fibroblast Culture and MTHFR Activity

Fibroblasts were cultured from skin-punch biopsy specimens obtained

from both parents and from the patient's stored samples. MTHFR activity

was measured at confluence, as previously described.6 All the assays

were performed in duplicate, with simultaneous assay of a normal

control.

Preparation and Sequence Analysis of Genomic DNA

Genomic DNA was isolated from the cultured fibroblasts from the

patient and both parents and from either blood or buccal cells from

other relatives. Each of the 11 MTHFR exons was amplified from genomic

DNA by the polymerase chain reaction (PCR) with the use of newly

designed intronic primers.7,8 (The sequences of the primers are listed

in Supplementary Appendix 1 with the full text of this article at

http://www.nejm.org.) The patient's and both parents' PCR products were

bidirectionally sequenced. A novel mutation in the patient's DNA at

nucleotide 1755 (exon 10) and two previously described frequent

polymorphisms at positions 677 (exon 4) and 1298 (exon 7) in the MTHFR

gene were analyzed in the genomic DNA from the parents and other

relatives with the use of the restriction enzymes NlaIII, HinfI, and

MboII, as previously described.3,4 Family members were also screened as

previously described for common polymorphisms in the genes encoding

enzymes that regulate folate and homocysteine metabolism; these

polymorphisms have been implicated in the pathogenesis of neural-tube

defects, other congenital anomalies, and cardiovascular and neoplastic

disease.9 The polymorphisms include those that encode methionine

synthase (MTR; the polymorphism results in the substitution of glycine

for aspartic acid at residue 919),10 methionine synthase reductase

(MTRR; the polymorphism results in the substitution of methionine for

isoleucine at residue 22),11 and cystathionine

----------

-synthase (CBS; the polymorphism is a 68-bp duplication).12

RNA Analysis

To evaluate the expression of an intact copy of the predominant 7.2-kb

MTHFR isoform,13 RNA was isolated from the patient's cultured

fibroblasts. A 2206-bp product containing the entire coding region was

amplified by PCR from the complementary DNA (cDNA) transcript and

sequenced in full. The 7.2-kb cDNA product was amplified as seven

overlapping fragments ranging from 1.0 to 2.2 kb in size, as verified

by gel electrophoresis. (The primers used to sequence the cDNA

transcript and to amplify the cDNA as overlapping fragments are listed

in Supplementary Appendixes 2 and 3, respectively, with the full text

of this article at http://www.nejm.org.) Bands corresponding to the

expected fragment sizes were excised, and the first 300 bases of the 5'

and 3' ends were sequenced to allow positive identification of each

fragment. Fragments from the patient and an unrelated control were then

compared.

Results

Enzyme Activity in Fibroblasts

The patient's MTHFR activity in two replicates was 0.76 and 0.03 nmol

of formaldehyde per milligram of protein per hour (normal mean value,

13.3±4.6 with the use of the current method of measurement6), with a

simultaneous normal control of 11.52 nmol of formaldehyde per milligram

of protein per hour. MTHFR activity in the father and mother (1.8 and

6.1 nmol of formaldehyde per milligram of protein per hour,

respectively) was reduced, with a control level of 9.5 nmol of

formaldehyde per milligram of protein per hour.

Genomic DNA-Sequence Analysis

The patient was found to be heterozygous for a novel mutation, 1755G

----------

A in exon 10, which causes a substitution of isoleucine for methionine

at residue 581 (M581I)14 (GenBank accession number, NM_005957).

Restriction-enzyme analysis confirmed the presence of the 1755G

----------

A mutation in the heterozygous patient, his father, his brother, one

uncle, and one aunt, but not in 100 control chromosomes. The patient

was also heterozygous for a 677C

----------

T mutation in exon 4 (resulting in a substitution of valine for alanine

at residue 222) and a 1298A

----------

C mutation in exon 7 (resulting in a substitution of alanine for

glutamic acid at residue 429). In addition to being heterozygous for

1755G

----------

A, the father was homozygous (TT) for the 677C

----------

T mutation and homozygous (AA) at 1298A (Figure 2). The mother was

heterozygous for both common polymorphisms and homozygous (wild type)

at 1755G. The sibling's haplotype was identical to that of the patient

in all coding regions. The novel mutation at 1755G

----------

A was therefore transmitted to the patient from a paternal chromosome,

in cis configuration with the 677C

----------

T mutation. Two of the father's four siblings had haplotypes identical

to the father's haplotype and were heterozygous for the 1755G

----------

A mutation and homozygous for the 677C

----------

T mutation (Table 1).

----------

View larger version (6K):

[in this window]

[in a new window]

Figure 2. Nucleotide Changes in the MTHFR Gene in the Patient and His

Parents.

In addition to the coding changes, the patient (the proband) and his

mother were heterozygous for a substitution of adenine for cysteine at

position 2355, which is 375 bases (in the 3' direction) from the stop

codon, on the same chromosome as the 1298C polymorphism. This

substitution is in a region of unknown importance. Asterisks denote

DNA-sequence variants. The open bars represent the MTHFR gene, and the

black bars the remainder of each chromosome in the pair.

View this table:

[in this window]

[in a new window]

Table 1. Polymorphisms in the Patient and Members of His Family.

We sequenced 25 to 40 bases beyond all intronic boundaries to look for

altered splice junctions. There were no substitutions in the 5' and 3'

untranslated regions flanking the MTHFR gene, within or proximate to a

putative binding site for a transcription factor or an actual start

site mapped by Gaughan et al.13 and Homberger et al.15 The DNA sequence

approximately 550 bp in the 3' direction from the MTHFR stop codon and

a 400-bp segment encompassing the distal 3'-polyadenylation site

contained several polymorphisms, but none at sites with recognized

functional significance.

We also performed genomic analysis of the genes encoding methionine

synthase, methionine synthase reductase, and cystathionine

----------

-synthase. Genotypes at these loci for all members of the pedigree are

provided in Table 1.

RNA Analysis

No size differences were observed among the seven MTHFR cDNA

fragments, indicating that the patient's fibroblasts expressed an

intact MTHFR transcript. The 2.2-kb product contained the entire coding

region of the transcript and was used to sequence a region beginning 50

bp in the 5' direction from the translational start site and ending 150

bp downstream of the stop codon. This product was of the expected

length, and no alternate splicing variants were detected. The entire

product was sequenced and compared with the published sequence14

(GenBank accession number, NM_005957). The presence of the heterozygous

common polymorphisms 677C

----------

T and 1298A

----------

C, as well as the heterozygote substitution 1775G

----------

A, was confirmed.

Discussion

The inactivation of methionine synthase by nitrous oxide has been

demonstrated with purified enzyme,16 in cultured cells,17,18 in animal

models,19 and in humans.20,21,22 The mean half-time of inactivation is

46 minutes. Residual methionine synthase activity more than 200 minutes

after the start of nitrous oxide administration approaches zero.21

Mice, pigs, and rats exposed to nitrous oxide have delayed recovery of

enzyme activity for periods of four days or more.19,23,24,25 Recovery

in cultured cells indicates that nitrous oxide-mediated inhibition is

irreversible, with de novo synthesis of the enzyme required to restore

activity.26

The untoward consequences of nitrous oxide anesthesia in our patient

are reminiscent of two recent case reports. In the first, an

eight-month-old child had acute neurologic deterioration six days after

an 80-minute period of anesthesia with nitrous oxide.27 In the second,

a four-month-old child was admitted because of hypotonia, dehydration,

and acidosis three weeks after surgery that had involved a 180-minute

period of anesthesia with nitrous oxide.28 Both children were found to

have severe dietary cobalamin deficiency. These instances of methionine

synthase inhibition have a time course and clinical features similar to

those observed in our patient but were nonlethal, perhaps because they

were elicited after only a single exposure to nitrous oxide. Moreover,

our patient had an inborn error of metabolism in an essential precursor

in a metabolic pathway, rather than an acquired deficiency, and nitrous

oxide was delivered on two occasions only a few days apart.

Severe MTHFR deficiency is an autosomal recessive disorder

characterized by progressive hypotonia, convulsions, and psychomotor

retardation. The clinical presentation may be subtle, with the disorder

manifested as developmental disability in the setting of moderate

homocystinuria and hyperhomocysteinemia and low-to-normal levels of

plasma methionine.29 Twenty-nine mutations in MTHFR are associated with

severe deficiency, with a resulting activity level that is usually 0 to

30 percent of control activity.7,8,14,30,31,32,33 Most patients are

heterozygous for multiple MTHFR substitutions; a small minority are

homozygous for mutations at this locus. The 1755G

----------

A substitution identified in our patient occurs in a phylogenetically

conserved region of the MTHFR protein (as assessed with BLASTP

software, version 2.2.1). This region, which is thought to be essential

for functional protein folding,34 is a " hot spot " for mutations leading

to MTHFR deficiency (1711C

----------

T, 1727C

----------

T, 1762A

----------

T, and 1768G

----------

A).7,8 The heterozygous presence of the 1755G

----------

A substitution in the patient's father, brother, one uncle, and one

aunt and its absence in 100 independent control chromosomes suggest

that it is not a benign variant.

Compound heterozygosity for the common MTHFR alleles 677C

----------

T and 1298A

----------

C, as seen in the patient, his mother, and his brother, causes

elevations in the plasma homocysteine level4 that are associated with a

50 to 60 percent decrement in enzyme activity.35 In the absence of

coding mutations elsewhere in the MTHFR gene or evidence of a mutant

splice variant, our patient's deficient enzyme activity may be

attributable to compound heterozygosity for the novel 1755G

----------

A mutation, with the prevalent 677C

----------

T polymorphism on the same (paternal) chromosome and the 1298A

----------

C mutation on the maternal chromosome. It has recently been shown that

when mutations causing severe MTHFR deficiency are expressed in cis

configuration with the common 677C

----------

T variant, the resultant phenotype is markedly aggravated.34

Every year, approximately 45 million persons in North America undergo

anesthesia, and nitrous oxide constitutes a major component in about

half these procedures.36 Because of the growing use of nitrous

oxide,37,38,39,40,41 patients with known mutations associated with mild

or severe abnormalities in folate-cycle enzymes are increasingly likely

to receive nitrous oxide. On the strength of the current findings, we

believe that patients with a diagnosis of severe MTHFR deficiency

should not receive nitrous oxide as anesthesia. In the case of

emergency procedures, patients whose clinical presentation fits that of

severe MTHFR deficiency, even if the disorder has not been diagnosed,

should also not receive nitrous oxide. In the case of elective

procedures, patients whose clinical presentation fits that of severe

MTHFR deficiency should be evaluated, and the diagnosis should be ruled

out before anesthesia with nitrous oxide is contemplated.

Supported by grants from the Doris Duke Foundation and the University

of Wisconsin Department of Anesthesiology Research and Development Fund

(to Dr. Hogan) and the Canadian Institutes of Health Research (to Dr.

Rosenblatt).

We are indebted to Singh Sekhon, Ph.D. (University of Wisconsin,

Madison), for the fibroblast cultures and to H. , M.D.

(Metabolite Laboratories, Denver), for the assays of total

homocysteine.

Source Information

From the Departments of Anesthesiology (R.R.S., K.H.) and Medical

Genetics (R.L.), University of Wisconsin Medical School, Madison; and

the Departments of Human Genetics, Medicine, Pediatrics, and Biology,

McGill University, Montreal (D.S.R.).

Address reprint requests to Dr. Hogan at the Department of

Anesthesiology, B6/319 Clinical Sciences Center, 600 Highland Ave.,

Madison, WI 53792, or at khogan@....

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and transcript variants of the human methylenetetrahydrofolate

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16. Frasca V, Riazzi BS, s RG. In vitro inactivation of

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18. Fiskerstrand T, Ueland PM, Refsum H. Folate depletion induced

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19. Kondo H, Osborne ML, Kolhouse JF, et al. Nitrous oxide has

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HG. Severe methylenetetrahydrofolate reductase deficiency: two novel

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34. Goyette P, Rozen R. The thermolabile variant 677C

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T can further reduce activity when expressed in cis with severe

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2000;16:132-138.[iSI][Medline]

35. Weisberg I, Tran P, Christensen B, Sibani S, Rozen R. A second

genetic polymorphism in methylenetetrahydrofolate reductase (MTHFR)

associated with decreased enzyme activity. Mol Genet Metab

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36. Orkin FK, SJ. Scope of modern anesthetic practice. In:

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37. Peretz B, Katz J, Zilburg I, Shemer J. Response to

nitrous-oxide and oxygen among dental phobic patients. Int Dent J

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39. Luhmann JD, Kennedy RM, Porter FL, JP, Jaffe DM. A

randomized clinical trial of continuous-flow nitrous oxide and

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40. Castera L, Negre I, Samii K, Buffet C. Patient-administered

nitrous oxide/oxygen inhalation provides safe and effective analgesia

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41. Krauss B. Continuous-flow nitrous oxide: searching for the

ideal procedural anxiolytic for toddlers. Ann Emerg Med

2001;37:61-62.[CrossRef][iSI][Medline]

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Nitrous Oxide and 5,10-Methylenetetrahydrofolate Reductase

Burman J. F., Kaufman J. L., Hogan K., Erbe R. W.

Extract | Full Text | PDF

N Engl J Med 2003; 349:1479-1480, Oct 9, 2003. Correspondence

This article has been cited by other articles:

.. (2003). Lucina. Arch. Dis. Child. 88: 1142-1142 [Full Text]

.. (2003). Fatal Combination: Nitrous Oxide Anesthesia and Methionine

Pathway Defects. Journal Watch Neurology 2003: 5-5 [Full Text]

.. Burman, J. F., Kaufman, J. L., Hogan, K., Erbe, R. W. (2003).

Nitrous Oxide and 5,10-Methylenetetrahydrofolate Reductase. N Engl J

Med 349: 1479-1480 [Full Text]

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I think many factors are at work here. Genetics , amount of exposure,

liver metabolism.....who knows? People who recreationally use nitrous

have presented to the ER complaining of numbness. In the article

posted it seemed the factors were genetic and a long exposure time.

Nitrous has been used for years in children and adults with no ill

effects. I sure that sniffing this stuff for over 20 years has

something to do with it. I now avoid nitrous with my adult patients as

I feel this contributes to post op nausea and vomiting. The short

amount of exposure that a child receives during an anesthetic should

cause no problems.

Sym

Date: Fri, 24 Sep 2004 08:58:41 -0700

From: White Light <whitelight@...>

Subject: Re: Re: anesthesia

Pardon me for asking, but if your experiencing these symptoms from the

possibility of nitrous and putting kids to sleep ..... what effect does

that

have on the children?

That kind of scares me.

Shauna

[ ] Re: anesthesia

i am a nurse anesthetist and I found this article on the internet. My

child is on the spectrum and we are going to have MTHFR testing done.

Currently I am taking folic acid for a high homocystine level( MTHFR

defect). I have heard that they think this gene has something to do

with folate metabolism which our kids need for metal metabolism. I

have been practicing for over 20 years and when we put kids to sleep we

use high flows of nitrous. Last year I started getting numbness in my

face and arms. I had a cat scan and they found nothing wrong. But

then I discovered I got the numbness after I did a room full of kids

that day. Still trying to figure that one out but I am now trying not

to do as many kids if possible. Pass this to your anesthesia

friend....Sym

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Thanks for the information. I was just curious as I have had about 5

operations as a child where I was put under so I wondered if my exposure had

contributed to my daughters condition.

Shauna

[ ] Re: anesthesia

>

>

> i am a nurse anesthetist and I found this article on the internet. My

> child is on the spectrum and we are going to have MTHFR testing done.

> Currently I am taking folic acid for a high homocystine level( MTHFR

> defect). I have heard that they think this gene has something to do

> with folate metabolism which our kids need for metal metabolism. I

> have been practicing for over 20 years and when we put kids to sleep we

> use high flows of nitrous. Last year I started getting numbness in my

> face and arms. I had a cat scan and they found nothing wrong. But

> then I discovered I got the numbness after I did a room full of kids

> that day. Still trying to figure that one out but I am now trying not

> to do as many kids if possible. Pass this to your anesthesia

> friend....Sym

>

>

>

>

> =======================================================

>

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Hi a,

I just wanted to wish you luck on your operation and a speedy recovery.

Susiea <twhwoman@...> wrote:

I'm having both knees replaced this coming Wednesday, 9-29,and I discussed anesthesia with my doc. He said that whenyou have one done, they can give you an epidural, and lightgeneral anesthesia, but you may be somewhat aware of thegoings on in the O.R. When doing both knees, the choice is aspinal, or general, since they don't want you waking upduring the procedure, at all. I opted for general, since Iknow too many friends who have had complications with thespinal, like bad, recurring headaches for a couple of weeks,and worse. I will still have an epidural catheter with apump, for post surgical pain. A nurse friend had theepidural catch two months ago, and she raved about it. Shesaid she had almost no surgical pain after her kneereplacement. Of course I'm nervous, but mostly excited aboutbeing able to resume my life, travel,

be active, all withoutthe horrible knee pain I've lived with for so many years.I went for a 3 1/2 hour trail ride today with four of myfriends, and my wonderful dogs, here in upstate NY. I liveon a small man, and the fall foliage is starting. Theweather was perfect, and we had a ball. This was my lastride of this season, and it was just perfect. When I askedmy doc how long it would take me to recover, he said about6-8 weeks. When I asked him if he would actually give me theokay to get on my horses in 8 weeks, he said YES, as long asI feel up to it. I sure hope he's right. Keep me in yourthoughts.................a

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  • 3 months later...

Hi,

I had a spinal and general anesthetic. The anaesthesiologist warned me that I did not want to wake up during surgery -- that the procedure could last a long time.

When I did come to, I wasn't drowsy, and it didn't seem to affect my recovery because I left the hospital in two day.

Carolethom42 <ethom42@...> wrote:

I forgot to ask who has had a spinal with THR? I am scheduled for one with a sedative. I see the advantages over general, but I really don't want to know anything that is going on.

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I had the same -- spinal + general anesthetic -- and it was fine. Had lunch a couple hours after I got back to my room. You definitely don't want to be aware during this surgery; it is noisy!

S.

-----Original Message-----From: Carol [mailto:carolann1312004@...] Sent: Monday, January 03, 2005 9:05 PMJoint Replacement Subject: Re: Anesthesia

Hi,

I had a spinal and general anesthetic. The anaesthesiologist warned me that I did not want to wake up during surgery -- that the procedure could last a long time.

When I did come to, I wasn't drowsy, and it didn't seem to affect my recovery because I left the hospital in two day.

Carolethom42 <ethom42@...> wrote:

I forgot to ask who has had a spinal with THR? I am scheduled for one with a sedative. I see the advantages over general, but I really don't want to know anything that is going on.

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I had an epidural with a sedative - I was out cold - I don't remember

a thing. I have heard of a few people who " woke up " while in the OR -

they said it was weird but not really scary. I don't think I'd like it.

(48)

RC2K Dr. Gross 3/24/04

>

> I forgot to ask who has had a spinal with THR? I am scheduled for

> one with a sedative. I see the advantages over general, but I

> really don't want to know anything that is going on.

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  • 5 months later...
Guest guest

Lee,.

I'm with you ... no interest in hearing all the sawing and pounding! Also, I was not about to let anyone stick a needle in my back. Just my quirk on that one, but I chose general anesthesia for both my THRs. Not ever having had the epidural, though, I can't compare recovery and post op pain.

Anesthesia

I apparently have my choice of anesthesias for this procedure... general or spinal. Doc recommended the spinal, but left it up to me. Said I'd get more pain relief (an hour or so) after surgery, and then, it would be an easier recovery than a general. What I DON'T want is to hear hammers and chisels and saws hacking away at my leg....

Any opinions????

lee

~ ~ ~ ~ ~ ~ Listen to the tide slowly turning, washes all our heartache awayWe’re part of the fire that is burningand from the ashes we can build another day(The Moody Blues “Story In Your Eyes”)

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