Early prenatal diagnosis of Meckel syndrome--a case report.

Meckel syndrome is a rare autosomal recessive disorder. The triad of the syndrome consists of occipital encephalocele, polycystic kidneys and postaxial polydactyly. At least two of these features are essential for the diagnosis, but other malformations such as microcephaly, cleft palate and ambiguous genitalia may also be present. The condition is considered invariably fatal. This report demonstrates that the prenatal diagnosis can in principle be established by ultrasound examination alone, and as early as 13 weeks' gestation.