Uniparental disomy as an unexpected cause of Meckel-Gruber syndrome: report of a case.

Background: Meckel-Gruber syndrome (MKS, OMIM #607361) is a rare pre- or perinatal lethal autosomal recessive ciliopathy caused by mutations in at least 12 known genes. It has a clinical and genetic overlap with other viable ciliopathies, especially Joubert syndrome and Joubert syndrome-related disorders. MKS is characterized by multicystic kidney dysplasia, central nervous system malformations (usually occipital encephalocele), ductal plate malformation of the liver, and postaxial polydactyly.