Meckel-Gruber Syndrome

Meckel-Gruber syndrome is an autosomal recessive disease characterized by the triad of multicystic dysplastic kidneys (>95%), encephalocele (>60%), and postaxial polydactyly (>50%).

On prenatal ultrasound, there are multicystic dysplastic kidneys: Enlarged, echogenic kidneys with or without macroscopic cysts. There is associated oligohydramnios and a small or absent bladder due to poor renal function. An encephalocele is seen in more than 60% of cases. The fetus may also have postaxial polydactyly that usually affects all four extremities, but this may be hard to detect due to the oligohydramnios.

Hepatic fibrosis is seen at autopsy, but is usually difficult to appreciate on prenatal ultrasound.

As an autosomal recessive syndrome, this is an important association to recognize on prenatal ultrasound, as it will affect counseling for the parents regarding subsequent pregnancies.