Autosomal dominant polycystic kidney disease (ADPKD) is a commonly inherited disorder (1/1000) in humans characterized by fluid-filled cysts in the kidneys. Defects in the PKD genes, PKD1 and PKD2, cause 85% and 15% of human ADPKD cases, respectively. Mutations in the PKHD1 gene cause autosomal recessive PKD (ARPKD). Mutations in several genes, including Nek8, cause PKD in mice. Although PKD affects 38% of Persian cats worldwide, making it the most prominent inherited feline disease, a causative gene has not been identified. Feline PKD is an autosomal dominant disease with clinical presentations similar to human ADPKD. Forty-three microsatellites were chosen from the feline genetic maps based on known homology with human chromosomal regions containing the PKD1, PKD2, PKHD1, and Nek8 genes. Linkage analysis using seven Persian cat pedigrees segregating for PKD has shown significant linkage and no recombinants (Z=5.83, theta=0) between the PKD disease phenotype and marker FCA476, which is within 10 cR of the feline PKD1 gene on Chromosome E3. This suggests that the PKD1 gene or another gene within this region may cause feline PKD. Further investigation into the cause of PKD will be valuable for feline health and provide insights into human ADPKD.