Bilateral periventricular nodular heterotopia with amniotic band syndrome.

The amniotic (constriction) band syndrome is characterized by distal ring constrictions, intrauterine amputations, and acrosyndactyly. External constriction by amniotic bands is the generally accepted mechanism: early amniotic rupture leads to formation of mesodermal fibrous strands that constrict, entangle, and amputate distal portions of limbs. Etiology is heterogeneous. Anecdotal cases involving central nervous system abnormalities (e.g., acrania, anencephaly, polymicrogyria, congenital bilateral perisylvian syndrome, neuronal heterotopia, septo-optic dysplasia, and spinal cord tethering) have been reported. We describe a 9-year-old girl with typical features of constriction band syndrome localized to the lower limbs who had also profound mental retardation and drug-resistant epilepsy associated with bilateral periventricular nodular heterotopia (a brain malformation of neuronal migration and proliferation caused by mutations in the X-linked filamin 1 gene [FLN1] on chromosome Xq28). The karyotype was normal, as was mutational screening for FLN1. The occurrence of bilateral periventricular nodular heterotopia in the context of amniotic band syndrome is novel (chance occurrence of both: 0.000004%).