An Italian family with autosomal dominant polycystic kidney disease unlinked to either the PKD1 or PKD2 gene.

We describe a family with autosomal dominant polycystic kidney disease in which molecular typing with closely linked markers for the PKD1 and PKD2 genes indicated absence of linkage. Thus, a third still unknown locus appears likely to be involved in disease development. This is the fourth "PKD3-linked" family described to date and the first from Italy.