There is little doubt that the search for the responsible genes in unifactorial neuromuscular disorders has been a phenomenal success. No less than 350 such disorders are currently listed in the Gene Table . Such information is of course essential for diagnosis, genetic counselling, prenatal diagnosis, attempts to understand pathogenesis and of course for new developments in gene therapy. But the majority of these unifactorial disorders are very rare. (Source: Neuromuscular Disorders)