PIK3CA and hemimegalencephaly: Similar and related disorders are caused by somatic mutations in the genes of the PI3K/AKT/mTOR (mammalian target of rapamycin) pathway, which include PTEN [14], PIK3R2 (MCAP) [7], AKT1 (Proteus syndrome) [15], AKT2 (asymmetric overgrowth and hypoglycemia) [16], and AKT3 (hemimegalencephaly) [17].