Although there is extensive allele heterogeneity, the ADPKD causing mutations are found in the PKD1 locus (chromosome 16 abnormality (16.p13.3); 85% of cases), the PKD2 locus (chromosome 4 abnormality (4p21); 15% of cases), and a rarer and newly discovered third locus, GANAB (chromosome 11 abnormality (11q12.3); 0.3% of cases); the GANAB locus is also associated with autosomal dominant polycystic liver disease [5]. This evidence concerns the gene PKD2 and autosomal dominant polycystic liver disease.