Clinical manifestations of autosomal recessive polycystic kidney disease (ARPKD): kidney-related and non-kidney-related phenotypes.

Autosomal recessive polycystic kidney disease (ARPKD), although less frequent than the dominant form, is a common, inherited ciliopathy of childhood that is caused by mutations in the PKHD1-gene on chromosome 6. The characteristic dilatation of the renal collecting ducts starts in utero and can present at any stage from infancy to adulthood. Renal insufficiency may already begin in utero and may lead to early abortion or oligohydramnios and lung hypoplasia in the newborn. However, there are also affected children who have no evidence of renal dysfunction in utero and who are born with normal renal function. Up to 30 % of patients die in the perinatal period, and those surviving the neonatal period reach end stage renal disease (ESRD) in infancy, early childhood or adolescence. In contrast, some affected patients have been diagnosed as adults with renal function ranging from normal to moderate renal insufficiency to ESRD. The clinical spectrum of ARPKD is broader than previously recognized. While bilateral renal enlargement with microcystic dilatation is the predominant clinical feature, arterial hypertension, intrahepatic biliary dysgenesis remain important manifestations that affect approximately 45 % of infants. All patients with ARPKD develop clinical findings of congenital hepatic fibrosis (CHF); however, non-obstructive dilation of the intrahepatic bile ducts in the liver (Caroli's disease) is seen at the histological level in only a subset of patients. Cholangitis and variceal bleeding, sequelae of portal hypertension, are life-threatening complications that may occur more often in advanced cases of liver disease. In this review we focus on common and uncommon kidney-related and non-kidney-related phenotypes. Clinical management of ARPKD patients should include consideration of potential problems related to these manifestations.