Meckel syndrome (MKS) is a rare, lethal, genetic, multiple congenital anomaly disorder characterized by the triad of brain malformation mainly occipital encephalocele (see this term), large polycystic kidneys, and polydactyly as well as associated abnormalities that may include cleft lip/palate (see these terms), cardiac and genital anomalies, central nervous system (CNS) malformations, liver fibrosis, and bone dysplasia.