X-linked AVPR2 mutations (∼90% of the cases)Autosomal recessive or dominant AQP2 gene mutationsPolyhydramnios, megalencephaly and symptomatic epilepsy (PMSE) syndromeInherited renal syndromes (nephropathic cystinosis, Bartter syndrome, nephronophthisis, etc.) The gene discussed is AVPR2; the disease is polyhydramnios, megalencephaly, and symptomatic epilepsy.