Sue,

If you have two recessive mutations, then chances of your son having any symptoms of MC are almost zero. There are a few mutations that seem to go either way, in other words it only takes one to cause symptoms and they behave more like Thomsen's. But that is not very likely.

If your son had a negative EMG, then you don't need to worry. He can still be a carrier of a recessive mutation and not show symptoms, but his children would only be affected if their mother also contributed a recessive mutation.

Having myotonia congenita does not affect life insurance. It should not affect health insurance, either, since the coding for it has changed. Myotonia congenita does not affect liver function so it would not be related to SGOT levels. That would more likely be either a viral infection or a medication.

Myotonic muscular dystrophy DOES affect liver function and often people confuse the two (it also affects life and health insurance eligibility). It's important for your doctor to understand the difference between the two because if he puts the wrong diagnosis code on prescriptions and insurance billing it can cause problems. The correct code is 359.22. Often doctors look up the term "myotonic" and read about MMD instead of MC and give misinformation.

Jan

Type of Myotonia: Thomsen's

Country: USA