P0715 Cornish Rex Unraveled

Barbara Gandolfi , University of California, Davis, Davis, CA
Leslie Lyons , University of California, Davis, Davis, CA
Hair is a unique structure characteristic of mammals showing different texture and color among individuals from different species and breeds. Although the genetic basis of several coat colors have been characterized in the cat, as well as the major gene controlling fur length, relative little is known about the genes influencing variation in coat growth and curly/woolly hair. The fur of a common cat consists of three hair types: long and straight guard hair of uniform diameter, thinner awn hairs, and fine undulating down hair of uniform thickness. A variety of rexoid and hairless breeds are documented to have alterations in their hair type, to date only two forms of autosomal recessive hypotrichosis and woolly hair have been characterized in Devon Rex and Sphynx. To identify a gene involved in controlling hair texture in the other autosomal recessive rexoid mutations, a genome-wide association analysis was performed in several cat populations, including the autosomal recessive woolly hair Cornish Rex. The breed showed association to SNPs on chromosome A1 (P raw = 2.308 x 10-28). In all cases, a causative mutation in a gene essential in maintaining the structural integrity of the hair shaft was identified and the disruption of the gene causes curly/woolly hair. The same mutation was identified as causative for curly/woolly hair in a second breed, the German Rex. This study represents the first successful GWA in the domestic cat.