MPDZ and congenital hydrocephalus: Genetic heterogeneity of congenital hydrocephalus is observed: mutations in the CCDC88C gene [MIM:611204] on chromosome 14 [14, 15] and in the MPDZ gene [MIM:603785] on chromosome 9 [16] are responsible for autosomal recessive hydrocephalus (respectively HYC1 [MIM:236600] and HYC2 [MIM:615219]).