Mechanisms and genetics in polycystic kidney disease. Mutations of PKD1 or PKD2 are identified in more than 90% of the patients affected by Autosomal Dominant Polycystic Kidney Disease (ADPKD). The severity of the renal disease is strongly influenced by the gene involved and the mutation type; the combination of genetic and clinical factors allows stratifying the risk to develop end-stage renal disease. Two new genes have recently been identified in genetically unresolved ADPKD patients, and seem to be associated with a better renal prognosis.