Congenital myotonic dystrophy; a report on thirteen cases and a review of the literature.

The congenital variant of myotonic dystrophy (CMD) is a severe disease with a high mortality. CMD is only seen in the offspring of mothers who themselves have myotonic dystrophy (MD). We present 13 patients with clinical symptoms of CMD and neuropathological findings of five of them. The most characteristic symptoms during pregnancy are reduced fetal movements and polyhydramnios. In the neonatal period generalized hypotonia, facial weakness, hyporeflexia, feeding and respiratory difficulties are present. Most of the children have a characteristic tented upper lip. The symptoms greatly diminish after a few weeks. All the children who survive the neonatal period are psychomotor retarded. On pathological examination no specific features were found in muscle tissue or in the brain. The pathogenesis and the cause of the maternal inheritance of CMD is not clear. A review of the literature is provided.