The natural history of congenital myotonic dystrophy: mortality and long term clinical aspects.

Although the genetic basis of the congenital form of myotonic dystrophy has recently been clarified, data as to outcome in terms of life expectancy and morbidity are scanty. Life table data based on a cohort of 115 patients with a confirmed diagnosis of congenital myotonic dystrophy are presented. The data suggest a 25% chance of death before 18 months of age and a 50% chance of survival into the mid-30s. The profile of disease and complications among survivors is also charted.