Autosomal recessive polycystic kidney disease (ARPKD) is a severe hepatorenal fibrocystic disorder. Its rareness and the variability of disease courses have been major obstacles for the establishment of clinical trials on treatment of kidney disease in ARPKD. In this observational study we characterized kidney disease progression in a very large cohort of up to 658 patients with the clinical diagnosis of ARPKD and identified risk factors associated with rapid kidney disease progression. …