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,

 

What type of CMT do you and your son have?

 

CMT Type 1 accounts for about 50% of the cases of CMT. Of the type 1 cases,

about 70-80% are Type 1A.  According to Dr. Byrd, about 1/3 of all CMT1A

patients have acquired the disease through a 'de novo' mutation, meaning they

did not inherit it from their parents but acquired it as a new genetic

mutation.  Once the person has acquired CMT1A, either through inheritance or de

novo mutation, he/she can then pass it to future children, 50/50% chance. If a

child doesn't inherit it, then there is 0% chance of passing it to

grandchildren. 

 

Note: De novo presentation percentage and inheritance patterns vary by CMT

type.  Click on the link Gretchen provided and then click on your subtype to

read Dr. Byrd's explanation of inheritance pattern for your type:

http://ghr.nlm.nih.gov/condition/charcot-marie-tooth-disease#inheritance

 

'De novo' doesn't mean the disease skipped a generation.  It means it's a

new appearance of the disease in a family line, which is not uncommon. Once

aquired, a de novo mutation is just as likely to be passed on to children as an

inherited mutation.

 

With regard to the genetic blood test, if you know what type of CMT your son

has, the cost may not be too bad for you to be tested for that one type.  The

cost only reaches several thousand dollars if the type of CMT isn't known and

they are testing for all the types for which there is a blood test.  If the

number of tests can be narrowed, the cost can be cut substantially. 

 

 

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Hi, ,

I'm actually not sure what type of CMT my son and I have. I'll have to

wait til he's back from holiday to ask him. Thank you so much for the Dr.

Byrd research--this is the most concise information I've yet come across

addressing that aspect of CMT.

Unfortunately, I have no information on the medical history of my dad's

side of my family, as he died young in WWII and had no living family members.

My mother's side of the family (coincidentally, with the surname Graham,

like you) appears to be completely free of CMT--and there are many Graham

aunts, uncles, cousins, etc., who are still alive and have no CMT whatsoever.

Thank you, too, for the " inheritance " link. As soon as I find out from my

son what our type of CMT is (he told me once but I didn't think it was

important at the time, so I promptly forgot it), I'll click on the link.

Going to another topic, I've mentioned before on this forum how my

increasing peripheral neuropathy has all but put a stop to any fine-motor hand

activities such as typing, fixing appliances, etc. So the other day I wanted

to swap out the wall light switch in my kitchen--something in the past I

would have done in five minutes while simultaneously eating a sandwich and

talking on the phone. I've installed countless wall switches in my life, but

when your fingers don't work right any more because they're now forever

numb, you just assign such chores to other people. It's lots easier and you

don't have to swear.

But that day I was in no mood--I wanted my new light switch installed and I

wanted it installed NOW. So for the first time in a couple of years, I

took screwdriver in hand and went to work. My former five-minute project

took the better part of 45 minutes, but I did it. I was so jacked up with

the success of my little task that I then went outside, removed the taillight

cover from my pickup truck and replaced a taillight bulb that had been

burned out for the past five or six weeks. Yeah, it took half an hour, but I

WON!

Yours for a CMT-free future,

In a message dated 9/17/2010 4:25:25 P.M. Pacific Daylight Time,

agraham2k@... writes:

,

What type of CMT do you and your son have?

CMT Type 1 accounts for about 50% of the cases of CMT. Of the type 1

cases, about 70-80% are Type 1A. According to Dr. Byrd, about 1/3 of all CMT1A

patients have acquired the disease through a 'de novo' mutation, meaning

they did not inherit it from their parents but acquired it as a new genetic

mutation. Once the person has acquired CMT1A, either through inheritance or

de novo mutation, he/she can then pass it to future children, 50/50%

chance. If a child doesn't inherit it, then there is 0% chance of passing it to

grandchildren.

Note: De novo presentation percentage and inheritance patterns vary by CMT

type. Click on the link Gretchen provided and then click on your subtype

to read Dr. Byrd's explanation of inheritance pattern for your type:

_http://ghr.nlm.nih.gov/condition/charcot-marie-tooth-disease#inheritance_

(http://ghr.nlm.nih.gov/condition/charcot-marie-tooth-disease#inheritance)

'De novo' doesn't mean the disease skipped a generation. It means it's a

new appearance of the disease in a family line, which is not uncommon.

Once aquired, a de novo mutation is just as likely to be passed on to children

as an inherited mutation.

With regard to the genetic blood test, if you know what type of CMT your

son has, the cost may not be too bad for you to be tested for that one type.

The cost only reaches several thousand dollars if the type of CMT isn't

known and they are testing for all the types for which there is a blood

test. If the number of tests can be narrowed, the cost can be cut

substantially.

[Non-text portions of this message have been removed]

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Hi ,

 

Congrats!  Great success story.  Wonderful perseverance.

 

My dad's an electrician and at 70, he's still changing light switches too,

though like you it takes him a lot longer now than it used to.  He loves

finding little aids to help him.  I can't help but wonder if a set of Built-up

Handles, a Power Grasper, and/or an electric screwdriver might keep

you changing light switches for many years to come.

 

When I was first diagnosed, learning about assistive technologies helped ease

some of my fears.  As I've lost function, I've incorporated many things into

my home.  My hands aren't numb, but I have lost fine motor function as well as

wrist/hand/thumb strength.  However, I still have a mean 'monkey' grip.  If

something is the right width and I can get all of my fingers wrapped around it,

I can grip fairly well and pull myself.  So my bathrooms and staircase are

equipped to allow me to play to this strength.

 

With my recent surgery, I have six weeks of limitations, i.e. can't bend at the

waist and can't pull myself.  I was very concerned at first when I learned this

from the occupational therapist.  How was I going to manage if I could only

push, not pull?  Within a few seconds, she had solutions.  I went home with

new devices and new strategies and it's working out just fine.  For the

unexpected challenges that arose after we got home, my husband and I worked

out solutions with additional devices.

 

If you've never met with an occupational therapist, you may want to check it

out.  Maybe he/she can have some helpful suggestions for you.  You may also

want to surf the Internet for sites that sell assistive devices.  There are

lots of gadgets out there.

 

There is nothing like the sense of freedom that comes from maintaining or

regaining independence with an assistive device.  I share your joy!

 

 

From: malamutesaloon@... <malamutesaloon@...>

Subject: Re: Genetics/Inheritance of CMT review

Date: Saturday, September 18, 2010, 3:35 AM

 

Hi, ,

I'm actually not sure what type of CMT my son and I have. I'll have to

wait til he's back from holiday to ask him. Thank you so much for the Dr.

Byrd research--this is the most concise information I've yet come across

addressing that aspect of CMT.

Unfortunately, I have no information on the medical history of my dad's

side of my family, as he died young in WWII and had no living family members.

My mother's side of the family (coincidentally, with the surname Graham,

like you) appears to be completely free of CMT--and there are many Graham

aunts, uncles, cousins, etc., who are still alive and have no CMT whatsoever.

Thank you, too, for the " inheritance " link. As soon as I find out from my

son what our type of CMT is (he told me once but I didn't think it was

important at the time, so I promptly forgot it), I'll click on the link.

Going to another topic, I've mentioned before on this forum how my

increasing peripheral neuropathy has all but put a stop to any fine-motor hand

activities such as typing, fixing appliances, etc. So the other day I wanted

to swap out the wall light switch in my kitchen--something in the past I

would have done in five minutes while simultaneously eating a sandwich and

talking on the phone. I've installed countless wall switches in my life, but

when your fingers don't work right any more because they're now forever

numb, you just assign such chores to other people. It's lots easier and you

don't have to swear.

But that day I was in no mood--I wanted my new light switch installed and I

wanted it installed NOW. So for the first time in a couple of years, I

took screwdriver in hand and went to work. My former five-minute project

took the better part of 45 minutes, but I did it. I was so jacked up with

the success of my little task that I then went outside, removed the taillight

cover from my pickup truck and replaced a taillight bulb that had been

burned out for the past five or six weeks. Yeah, it took half an hour, but I

WON!

Yours for a CMT-free future,

In a message dated 9/17/2010 4:25:25 P.M. Pacific Daylight Time,

agraham2k@... writes:

,

What type of CMT do you and your son have?

CMT Type 1 accounts for about 50% of the cases of CMT. Of the type 1

cases, about 70-80% are Type 1A. According to Dr. Byrd, about 1/3 of all CMT1A

patients have acquired the disease through a 'de novo' mutation, meaning

they did not inherit it from their parents but acquired it as a new genetic

mutation. Once the person has acquired CMT1A, either through inheritance or

de novo mutation, he/she can then pass it to future children, 50/50%

chance. If a child doesn't inherit it, then there is 0% chance of passing it to

grandchildren.

Note: De novo presentation percentage and inheritance patterns vary by CMT

type. Click on the link Gretchen provided and then click on your subtype

to read Dr. Byrd's explanation of inheritance pattern for your type:

_http://ghr.nlm.nih.gov/condition/charcot-marie-tooth-disease#inheritance_

(http://ghr.nlm.nih.gov/condition/charcot-marie-tooth-disease#inheritance)

'De novo' doesn't mean the disease skipped a generation. It means it's a

new appearance of the disease in a family line, which is not uncommon.

Once aquired, a de novo mutation is just as likely to be passed on to children

as an inherited mutation.

With regard to the genetic blood test, if you know what type of CMT your

son has, the cost may not be too bad for you to be tested for that one type.

The cost only reaches several thousand dollars if the type of CMT isn't

known and they are testing for all the types for which there is a blood

test. If the number of tests can be narrowed, the cost can be cut

substantially.

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Hi ,

Good to hear from someone with South African connections. Pretoria

is beautiful this time of year- the purple jacaranda trees will start

blooming in a few weeks. Have to say I don't like reptiles,though:-)

Having been newly diagnosed with CMT, I am certainly no expert. And

with all the information on CMT that is out there, I can see why it

can be confusing, especially if you need to find out what type of CMT

you have. From my understanding (and please someone correct me if I

am wrong), if you have autosomal dominant CMT it can only be directly

passed on to the next generation, and you inherited it from one of

your parents. If it is autosomal recessive it can be carried by

someone who doesn't necessarily have the CMT and under the right

conditions be passed on to someone further down the family tree. I

suspect that mine is what they call " de novo mutation " .

No one in my family has it, but one of my genes has mutated to start the CMT

with me and it therefore could be passed down to my kids (but my kids are both

adopted so that will not be the case for our family). Although, as I think of

my Dad (who died a year ago at the age of 82), I am wondering if he might have

had CMT. If so, the symptoms were so mild and late onset that we never

suspected it to be anything other than old age (high arches, slightly curled

toes, complaints about his

shoes bothering his feet, balance problems, hearing loss, a weak

ankle prone to sprains). However, he loved to hike and walk, and was

out hiking into his late 70's, so I really don't know.

As far as diagnosis goes- I had peripheral neuropathy symptoms

(numbness and weakness) and also very slow NCV's on 2 occasions

approximately 6 years apart. My neurologist here first tested me for

diabetes, Vitamin 12 deficiency, thyroid, cholesterol- a very

thorough blood test- to determine if there were any other causes for

my neuropathy. When those tests came back negative for other causes,

she said my neuropathy was either CIDP or CMT. The lumbar puncture

was given to confirm CIDP (where the protein levels in the spinal

fluid are high). My spinal fluid also tested negative- so that left

her with the CMT diagnosis (on the basis of elimination of other

possible causes). Of course there is no way of knowing what kind of

CMT I have without having genetic testing. I think a biopsy may also

further confirm the diagnosis.

I suspect I may have CMT1A, but that is only a guess on my part after reading

the link that Gretchen sent.

I can see where CMT can be confusing since there are so many sub-

types of the disease. However, since there is no treatment or cure,

and since there is no way of predicting how fast or slow the disease

will progress, for me, I don't think knowing my subtype really helps

me in any way.

Blessings,

Barb Bartz

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