The mechanism of other dominant mutations such as the one that causes myotonic dystrophy is not yet known.
When the DNA was switched on the mice showed all the symptoms of myotonic dystrophy.
Other more common types of MD are Becker's, myotonic dystrophy, limb-girdle MD, and facioscapulohumeral MD. MD is more common in boys.
Myotonia: Myotonias include myotonic dystrophy, myotonia congenita, paramyotonia congenita, and neuromyotonia.