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Charcot-Marie-Tooth UK
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Family planning

Hey everyone. I'm not really sure how this forum works, or if I belong here.

My husband was diagnosed with HNPP. Before we found out, we were trying to have a baby. I have since put that on hold. My fear of HNPP has somewhat taken over.

With my husband having HNPP, I know our child has a 50% chance of also having it. My question is, will he only pass down HNPP or is their a possibility of him passing down a more serious type of CMT also involving that gene?

Thank you.

4 Replies

Hi Olivia. I'm sorry to hear about your situation. I don't really know the answer, but would suggest your Neurology Consultant would be the best place to start.


Thank you.

I believe if I'm not mistaken that HNPP is passed down the same way as CMT.

Could anyone tell me how it works with CMT. Say you have CMT1. When you have children, will they only get CMT1 also, or could they end up getting CMT2 and so on? Or do you only have the chance of passing on the type that you have?

With CMT you have the duplication of the gene, and with HNPP you are missing one.

Is anyone aware if someone with HNPP can have a child who ends up with CMT. Or the opposite. If someone with CMT can have a child who get HNPP.

I hope I explained that okay. It sounded okay in my head, but not sure how it reads when I try and explain it. Lol


No, your children can only inherit genes the parents have! If you have type 1a, there's a 50/50 chance of passing on that.

Now, we have heard of a case where one parent has HnPP and the other has type 1a. The child inherited both, but since one condition, as you say, is missing a gene, and the other has too many, the child ended up completely normal! One cancelled out the other! And that is how researchers KNOW for absolutely definite, that too much PMP22 causes CMT! Amazing, isn't it?


No, he can only pass on HNPP. You can only pass on the genes you have, not ones you haven't, if that makes sense!

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