Myotonia Congenita

[Oceanblu]

Not sure where is best to post this, posting here for traffic.

I have recently found out I’m pregnant (5+3). My partner, his sister and his mum all have Myotonia Congenita. It is debilitating for his sister and sometimes his mum, however it doesn’t affect him as bad.

My partner goes to a specialist every year for a review. He can remember being told a number of years ago that there is a chance his future children will inherit the condition. I’m wondering if he should get in touch with the specialist and ask whether he is definitely a carrier, I don’t know if this is something they can confirm.

I’m wondering if there is any testing that can be done in pregnancy for the condition, or whether it is a case of waiting to find out when the baby is here. Can anyone offer any advice?

Hi there. My partner has this disorder. It is very rare so very unusual to meet others with it! He has the autosomal dominant version - Thomsens disease. I believe this means that the disease passes down through the mother's side. My partner's Thomsens was determined through the hospital doing genetic testing - we have details of the specific genetic mutation. We do not have children (by choice) but were offered genetic counselling if we were planning to. One of my partner's brothers has two children, neither seem to be affected. The other brother also has two children, one of whom has been confirmed to have the disorder. I'm not sure if this was determined through genetic testing after birth (I don't believe any testing was offered or available during pregnancy), or just from the obvious symptoms they are showing - though he is a very happy and very active child! Perhaps best to start with your partner's medical team for advice? Good luck and congratulations on your pregnancy.

Please contact the fetal medicine team via your midwife urgently and say that you need to talk urgently because your baby is at risk of an inherited genetic condition and you want to understand the possibilities. Even though it is so early I would start trying to book your pregnancy in the normal way (your gp,surgery will know) and explain why you are contacting the, early.
If your partner has been diagnosed then your baby is unfortunately at risk (50%) of inheriting the condition, which tends to get worse in each generation (genetic anticipation).
Tests can be done if the mutation is known but you need to have a proper discussion with somebody who has the information. Is your husband seen in a clinic near you? It may also be worth talking to them.
Testing can often be done after about 13 weeks but is dependent on lots of factors.
in summary - you need to talk to someone who knows your personal and family history.

That’s really helpful, thank you.

My partners family have never come across anyone else with the condition.

My booking appointment with my midwife was meant to be at 12 weeks (!). I called my GP to state my concerns as above and they were useless. I did however call the maternity booking team and they have brought my appointment forward to next month when I will be 9 weeks.

This will give my partner time to get in touch with his consultant and get as much info as possible

That sounds great.
congratulations on your pregnancy.