Many of these conditions are related to neurodevelopmental disorders such as tuberous sclerosis complex (TSC), focal cortical dysplasia type 2 (FCD2), hemimegalencephaly (HME), Smith–Kingsmore Syndrome (SKS), POLR2A-related syndrome associated with epilepsy and mental retardation, polyhydramnios, megalencephaly, symptomatic epilepsy (PMSE), PTEN syndrome, DEPDC5-related syndrome, and PI3K-related overgrowth syndrome (PROS). The gene discussed is POLR2A; the disease is tuberous sclerosis.