Re: Diagnosed but negative blood test

[Guest guest]

My son is still going thru the blood tests. He was 8 when he went thru the nerve

conduction test (they sedate children, he didn't feel a thing) I was told they

are sure it's CMT. However they can only test for one panel at a time (something

like 12 types of CMT per panel) and there are hundreds of types he could have.

So finding the correct panel to test is like finding a needle in a haystack. If

anyone out there reads this and finds I am mistaken about something let me know.

Anyway, I am frustrated about it because it seems that they have jumped to this

conclusion when there are so many other things it could be other than CMT,

including a reaction to drugs he was given constantly since infancy which now

have been shown to cause peripheral neuropathy. If this is the culprit, there

are infusions which have been known to reverse some of the neuropathy. I am told

it can wind up costing tens of thousands of dollars just to continue to test for

CMT. I am stumped. What if it isn't CMT after all?

In His Most Merciful Name,

Ziegler

[Guest guest]

Ditto, Jackie.

I was give a diagnosis of CMT but blood test was negative. No history of it in

my family (my mother did have polio, though, and I

was born during the time she had it). She completely recovered a few years

later, thank goodness. I was given a dx of MS for three years before the CMT

dx, and it was bittersweet to find out I had CMT all along instead of MS. I

will gladly take the CMT dx, but MS is not genetic and now I wonder if my grown

kids will show signs later in life, like I did.

Looking back, I had symptoms in my second decade and just thought I was not

strong to go on pointe in ballet. I danced for about seven years but could

never go on point on my left foot.

Now both of my feet are affected and it is impossible to walk on the toes or

heels.

Karon in San Diego

[Guest guest]

I have had a CMT diagnosis for 20 years. I have had genetic testing done 3

different times, and each time it showed negative. They even tested me for SMA.

I know there are several people on this site who have had a negative blood test.

The EMG should show whether it is axonal or myelin related which helps identify

over CMT 1 type or CMT 2 type.

I have no family history and have been unable to test my son (although he shows

no symptoms and had a neurologist check him out, although no EMG was done on

him)

Jackie

Diagnosed but negative blood test

 

There is a lingering question mark whether CMT is the right diagnosis although 2

neurologists have given us the diagnosis. Both my husband and son took the blood

test to determine what type of CMT they have and both of their tests came back

negative. However, the neurologist said it doesn't change his diagnosis. My

husband had the electric connectivity test in his nerves and does have very

clear nerve damage although it doesn't affect him symptomatically. We are not

going to give this test to our son because it was SO PAINFUL for my husband (he

needed smelling salts!). Does anyone out there have a CMT diagnosis with

negative blood tests? Thank you!

[Guest guest]

Hi ,

When you say " Negative Blood Test " do you mean the Athena Labs screening for the

type/subtype of CMT a patient might have?

If so, then yes, I have CMT Type 1 as determined by the EMG & Nerve conduction

tests. However, my blood test came back negative for all of the CMT subtypes

that Athena can test for. That does not mean that I don't have CMT. All it

means is that they have not developed commercially available tests for all of

the subtypes of CMT and/or that they may have not discovered all of the possible

subtypes.

[Guest guest]

As Gretchen stated, there are over 40 types of CMT that have been identified so

far.  However, at this point, there is a genetic blood test available for less

than half of these identified types of CMT.

 

A positive blood test result means that you do have CMT, but a negative result

doesn't mean you don't have it.  It just means you don't have one of the types

that is identifiable with a blood test.  You could still have one of the other

types of CMT, for which there hasn't been a blood test developed yet.

 

A doctor has the option of ordering a partial CMT blood test panel or the

complete panel of available tests.  Obviously, the full test is more expensive

than the partial panel, so a doctor will typically try to narrow down the type

of CMT through the use of a NCV test and order just the tests that are more

likely to identify the CMT type.  If the partial test is negative, then the

remaining tests may be ordered, if appropriate.  If all the tests are negative,

the person may have one of the other types of CMT or no CMT at all.

 

[Guest guest]

,

Oh yes, I don't know about common, but it can be the case. My neurologist

*thinks " I have CMT 2 but only as CMT 1 and all the variants have come back

negative.....

Then again he thinks I'm " interesting " . I've given up being flattered by

interesting. These days I'd settle for boring!!

Regards

Fiona

Glasgow Scotland

[Guest guest]

okay...so the nerve conduction test is the first test to positively say you have

CMT and nothing else, and then the blood test determines the type/subtype?

In His Most Merciful Name,

Ziegler

[Guest guest]

The EMG/NCV can tell if a person has CMT Type 1 or 2. Skin biopsy can only tell

that too. For specific subtypes then it's the DNA blood testing - also maybe for

testing Type X an MRI. If you say there's no apparent family history, and

EMG/NCV shows substantial motor/sensory loss, it may be from a recessive gene or

a new mutation.

Gretchen

Gretchen