Early fatal pontocerebellar hypoplasia in premature twin sisters.

We report clinical, neuroradiological and neuropathological findings of monozygotic twin sisters born at 30 weeks' gestation, with pontocerebellar hypoplasia (PCH) similar but not identical to type 2 PCH. They presented with hypertonia, jitteriness, spontaneous and provoked myoclonic jerks (hyperekplexia), apnoeic episodes, and progressive microcephaly. They died at 7 weeks of age from respiratory failure.