THE SYNDROME OF AUTOSOMAL RECESSIVE PONTOCEREBELLAR HYPOPLASIA, MICROCEPHALY, AND EXTRAPYRAMIDAL DYSKINESIA (PONTOCEREBELLAR HYPOPLASIA TYPE-2) - COMPILED DATA FROM 10 PEDIGREES

The syndrome of autosomal recessive pontocerebellar hypoplasia, microc ephaly, severely impaired mental and motor development, and extrapyram idal dyskinesia is a distinct system degeneration, previously designat ed pontocerebellar hypoplasia type 2 (PCH-2). To further characterize its clinical and neuroimaging features, we compiled data from 10 nonre lated pedigrees. Six pedigrees were Dutch, two Swedish, and two German . All 16 patients showed an identical profile of virtually absent deve lopmental milestones, early-onset severe chorea, and microcephaly toge ther with pontocerebellar hypoplasia. Family distribution supports aut osomal recessive transmission. The present data support the PCH-2 phen otype as a distinct neurogenetic entity.