RELN and polymicrogyria: Mutation of the reelin(RELN) gene causes autosomal recessive lissencephaly with cerebellar hypoplasia.3 Mutations in the tubulin a-1A (TUBA1A) gene are known to be associated with a distinctive radiologic phenotype consisting of posteriorly predominant lissencephaly with corpus callosal dysgenesis, cerebellar and brainstem hypoplasia, and polymicrogyria.8 In half of the patients having Cobblestone lissencephaly(type II lissencephaly), there is a mutation in POMT1, POMT2, POMGNT1, FKTN, FKRP, and LARGE genes.