Exome sequencing of families with megalencephaly-polymicrogyria-polydactyly-hydrocephalus syndrome (MPPH) identified a recurrent missense variant in the PIK3R2 gene in 11 unrelated families; in one of these families, an affected male sibling was also diagnosed with Asperger syndrome, while one of two affected female siblings also had Asperger-like features (Riviere et al., 2012).
Phosphatidylinositol 3-kinase (PI3K) is a lipid kinase that phosphorylates phosphatidylinositol and similar compounds, creating second messengers important in growth signaling pathways. PI3K functions as a heterodimer of a regulatory and a catalytic subunit. The protein encoded by this gene is a regulatory component of PI3K.
Type of Disorder
De novo germline and postzygotic mutations in AKT3, PIK3R2 and PIK3CA cause a spectrum of related megalencephaly syndromes.