ADPKD is caused by mutations in PKD1 (16p13.3; OMIM ID: 601313) in approximately 85% of the cases (The European Polycystic Kidney Disease Consortium 1994), and in PKD2 (4q21; OMIM ID: 173910) in the remaining 15% (Mochizuki et al. 1996). The gene discussed is PKD1; the disease is autosomal dominant polycystic kidney disease.