[Congenital myotonic dystrophy].

Congenital myotonic dystrophy is a distinct entity causing severe hypotonia and other neuromuscular manifestations. The disease is usually inherited from the mother and shows a more severe course than the adult form of dystrophia myotonica. Congenital myotonic dystrophy is associated with increased perinatal mortality. We describe a case with this disorder and discuss the differential diagnosis in relation to other neuromuscular disorders causing hypotonia in early life.