Congenital Myotonic Dystrophy Diagnosed in an Adolescent Period

Type 1 myotonic dystrophy (DM1) is an autosomal-dominant inherited disorder with multisystem involvement, caused by an abnormal expansion of CTG sequence of the dystrophia myotonica protein kinase (DMPK) gene on chromosome 19. Congenital myotonic dystrophy (CDM) is the most severe phenotypic form of DM1. CMD tends to be observed in congenitally affected fetus or neonates born to affected mothers. We report a patient confirmed as CDM during the adolescent period.