Multicystic renal dysplasia, bilateral

Other Names: MRD; Pelvi-ureteric junction obstruction; PUJO; Hydronephrosis due to PUJO

Bilateral multicystic dysplastic kidney (MCDK) is a lethal form of multicystic dysplastic kidney (MCDK,), a congenital anomaly of the kidney and urinary tract (CAKUT), in which both kidneys are large, distended by non-communicating multiple cysts and non-functional.

Epidemiology

The prevalence and incidence of bilateral MCDK are unknown.

Cause

MCDK results from disrupted nephrogenesis but the exact pathogenic mechanism is still unknown. Disturbed formation of nephrons could result from impaired fetal urine flow early in development. Mutations in the HNF1B gene (17q12), coding for hepatocyte nuclear transcription factor 1β, are known to cause unilateral MCDK and have only rarely been reported for bilateral cases. MCDK is also linked to gestational diabetes and to the use of some medications during pregnancy, such as anti-epileptic drugs.

Signs and symptoms

Bilateral MCDK may be suspected antenatally at routine ultrasound scans, with the majority detected around the 20th week of gestation. It is considered a lethal entity, and most pregnancies are terminated. When born, such infants present with features of the Potter sequence (constellation of signs resulting from prolonged in utero oligohydramnios) including severe pulmonary hypoplasia and severe renal failure, limb anomalies and facial dysmorphic features, and generally die shortly after birth.

NIH genetic and rare disease info

• NIH info on Multicystic renal dysplasia, bilateral

Multicystic renal dysplasia, bilateral is a rare disease.