Charcot-Marie-Tooth UK
1,241 members495 posts

The difference between HNPP and CMT 1A

Hi can someone tell me the difference between these two diseases? I have HNPP but it is listed under the CMT drop down and many of the symptoms are the same I tell people now I have HNPP/CMT as no one sems to know an

bout HNPP but people recognise CMT. Why is this? Surely they are two of the same disease? I have had HNPP since diagnosis in 1999 but since join ing the CMT group, I am now confused as to which disease I have and whether it is type 1A or some other type?

Please help a confused sufferer!


2 Replies

Hi Pam

HNPP and CMT1a are two distinct conditions - in fact HNPP is the genetic opposite of CMT1a! CMT1a is caused by a duplication in a particular gene on chromosome 17 - ie, people with that have three copies of this gene. HNPP is caused by the same gene, but it's missing - ie, only one copy!

The two condition are often lumped together because of this - and because some of the symptoms can be similar with the weakness in arms and legs - but your weakness is caused by the pressure palsies causing damage to the nerves.

If you were diagnosed as having HNPP, you definitely still have that, and not CMT1a - we just cover both at CMT United Kingdom because of their similarities. You can find out more about HNPP here -

Hope this helps!



hi pam i to have hnpp ,i think both disease can range from mild to disabling,when people ask me what i have wrong with myself i tell them i have damaged nerves ,which is true and they seem to understand that more ,


You may also like...