Diffuse pachygyria with cerebellar hypoplasia: A milder form of microlissencephaly or a new genetic syndrome?

We report on 2 families with diffuse pachygyria and cerebellar hypoplasia, who presented hypotonia, ataxia, seizures, and developmental delay since in fancy. Computed tomography (CT) and magnetic resonance imaging (MRI) reveal ed decreased gyral formation in the cerebral cortex and marked hypoplasia i n the cerebellum. Cerebellar hypoplasia is often associated with type 2 lis sencephaly; however, our cases showed no polymicrogyria, and their clinical findings were quire mild compared with those of microlissencephaly, Their characteristic phenotype suggested a new genetic syndrome, which was possib ly inherited as an autosomal recessive trait.