Pontocerebellar hypoplasia type 2 (PCH2): report of two siblings.

We describe two sisters affected by pontocerebellar hypoplasia type 2 associated with microcephaly, hypertonia, severe choreiform movements, an almost complete lack of psychomotor development, and generalized tonic-clonic seizures. Clinical and neuroradiological findings ruled out other conditions associated with pontocerebellar hypoplasia, i.e. pontocerebellar hypoplasia type 1, carbohydrate-deficient glycoprotein syndrome, and olivopontocerebellar hypoplasia/atrophy.