MTOR and Megalencephaly - polymicrogyria - postaxial polydactyly - hydrocephalus: In recent years, both megalencephaly-capillary malformation syndrome (MCAP, OMIM 602501) and megalencephaly-polymicrogyria-polydactyly-hydrocephalus syndrome (MPPH, OMIM 603387) have been shown to result from gain-of-function mutations in the PI3K-AKT-mTOR pathway (mTOR-pathway) [2].