CMS's are genetic. There are over 100 different mutations. There are 3 basic types of CMS (simplistic but it will help):

1. Zero amount of acetylcholine (not a lot works)
2. Too much acetylcholine (Quinine, etc. used)
3. Not enough acetylcholine (Mestinon, 3,4 DAP used)

The ones that have too much acetylcholine do not usually get worse with exercise. But, again, there are exceptions to every rule. So, yes, if she had a sodium channel CMS, giving her Mestinon would make her worse. The more common one is where there isn't enough acetylcholine. There are variations within that too!

You do NOT want a pediatric expert on CMS! You want someone who has the absolute MOST knowledge of CMS. If that ends up being an "adult" doctor, see that one. This stuff is so rare that you want the best doctor possible. Because, yes, the wrong med could make her worse.

If you find out she has AChR antibodies for MG, then chances are that she has MG. A lot of the CMS's tend to run in families. Is there anyone else in your family who has these kind of issues?

I honestly believe that the way to go is Mayo. This stuff is just so specialized and most "regular" neuros don't know all of this. There are MG experts who don't have a clue about CMS.

I'm with you. I wouldn't want to get an incorrect diagnosis. You need to be sure because of the difference in treatments for all of these diseases. Genetic diseases do not respond to immunosuppressants/steroids because they are not autoimmune diseases.

Okay, go take a break and let all of this soak in. We're here to help.