A clinical study of germline mutation screening for ADPKD-genes PKD1 and PKD2 in a population of German patients recruited by both nephrologists and non-nephrologists all of whom presented with ADPKD-type features found an overall prevalence of 32.7/100,000 (~ 0.6 in 2000) individuals, meeting the criteria for a rare disease [18]. Here, PKD2 is linked to autosomal dominant polycystic kidney disease.