Neonatal myotonic dystrophy associated with prenatal ventriculomegaly. A case report.

Myotonic dystrophy is an autosomal dominant neuromuscular disease in which the maternal manifestations may be mild or subclinical. However, the congenital form, transmitted only from affected mothers, is reported to have a neonatal mortality rate as high as 50%. Ultrasonographic features of pregnancies with affected fetuses include hydramnios and decreased fetal movement, breathing motion and swallowing. Several reports have also noted an occasional infant with ventriculomegaly or hydrocephalus. It appears that prenatal ventriculomegaly may also be an occasional ultrasonographic finding heralding neonatal myotonic dystrophy.