I am a homeopath and although some remedies can help alleviate minor symptoms caused by myotonia congenita (like muscle soreness), there is no cure and there is nothing that makes a significant difference. The mutation is part of our DNA.
Please read this blog with posts and articles about Dr. Bhardwaj (warning, this is adult subject matter):
Since you have myotonic muscular dystrophy you might want to consider taking CoQ10 to see if it helps. I don't think any homeopathics will make a difference overall, but it might be beneficial for you to have a consultation with a professional homeopath for specific symptoms.
Thanks. I take a list of vitamins my doctor suggested including CoQ10. I was most interested in what she had to say as the site was from India, and I have heard that Ayurvedic medicine (from India) has helped a lot of people with various forms of MD. As they thought I had FSHD until last week, although I suspected for months that I had myotonic dystrophy, i am just catching up on the information. And you can see that the carrot juice in the morning which was recommended for FSHD might not have been the best thing for me! ;)