Megalencephaly-Polymicrogyria-Polydactyly-Hydrocephalus Syndrome-1

**Semantic type:** Disease or Syndrome

**Definition:** An autosomal dominant condition caused by mutation(s) in the PIK3R2 gene, encoding phosphatidylinositol 3-kinase regulatory subunit beta. It is characterized by mild to severe intellectual disability, megencephaly, polymicrogyria, and postaxial polydactyly.

**Synonyms:** - MPPH1