Meckel Syndrome (MKS) is a perinatally lethal, autosomal recessive disorder, caused by defects in primary cilium formation. It is characterized by a constellation of anomalies, most notably polydactyly, multiple renal cysts, and central nervous system malformations.
To date, three fetuses from two unrelated families have been identified with Meckel Syndrome type 10 (MKS10). These cases exhibited the classic triad of occipital encephalocele or other posterior fossa anomalies, postaxial polydactyly of the hands and feet, and renal cystic dysplasia that define Meckel syndrome. In some instances, additional anomalies were noted, including anencephaly, bifid uvula, microphallus with hypospadias, bowed long bones, ductal plate malformation on liver histopathology and cases with normal renal morphology.
Joubert Syndrome type 34 has been reported in two families. The hallmark features included the molar tooth sign on neuroimaging and polydactyly. Additional findings observed in affected individuals included seizures, interpeduncular heterotopia, cleft palate, patent ductus arteriosus, hearing loss, facial dysmorphism, and hypospadias or micropenis.
These two disorders are allelic disorders with significant phenotypic overlap.
B9D2