ARegPKD is a multinational European ARPKD registry with involvement of EU-neighbouring countries. Within this project two renowned clinical research consortia in pediatric nephrology, i.e. the German Pediatric Nephrology Association (GPN) and the European Study Consortium for Chronic Kidney Disorders Affecting Pediatric Patients (ESCAPE Network), join forces with leading geneticists and pathologists to advance the pathophysiological understanding, provide an observational evidence base for unified clinical treatment concepts, establish clinical and biomarkers predicting the risk of early and progressive disease, lay the foundation for innovative translational research toward novel therapeutic targets, and pave the way for clinical trials for this disorder.