What is it?
a form of muscular dystrophy accompanied by myotonia.
The exact cause of Myotonic Dystrophy is unknown however the genetic change responsible has been identified.
The genetic change (mutation) that causes Myotonic Dystrophy is in the DMPK gene found on chromosome 19.
The muscle wasting and weakness develop in their lower legs, hands, neck and face. They also have stiffness and tightness of their muscles (calledmyotonia), so they are slow to relax certain muscles after using them. Not being able to release their grip on in a handshake or a doorknob is one example of this problem.