Nephrologie im Dialog
Polycystic kidney disease is a major cause of end stage renal disease in Europe. The adult-onset Autosomal Dominant Polycystic Kidney Disease (ADPKD) is a very frequent monogenetic disease and a major cause of dialysis-requiring end stage renal disease.
Autosomal Recessive Polycystic Kidney Disease (ARPKD) is the rare and often severe pediatric form of cystic kidneys. It has an early impact on child health. Kidneys are often grossly enlarged at birth and there is mandatory hepatic involvement. ARPKD occurs with an estimated incidence of 1:20.000. Still, ARPKD is responsible for up to 50% of patients with cystic kidneys in pediatric centers.
There is major unexplained phenotypic variability in ARPKD. The disorder is caused by mutations in a single gene, PKHD1. PKHD1 encodes a huge transmembrane protein called Fibrocystin, which localizes to primary cilia of cells, classifying ARPKD as a ciliopathy. Fibrocystin is also involved in the regulation of pathways affected in ADPKD.
The pathophysiology, clinical heterogeneity and long-term evolution of the disorder remain poorly understood, explaining why there is currently no causative treatment for ARPKD. Even in most-advanced medical centers mortality remains high. Kidney dysfunction can be progressive leading to early end stage renal failure. Combined liver and kidney transplantation may be required in case of renal and hepatic failure. Severe and very early arterial hypertension is common and treatment often remains challenging. No clinical classifications, clinical risk factors or treatment guidelines for these challenges have been established so far and experience remains sparse even in large pediatric centers.