The colour variant colourpoint determines if a cat is carrier of a form of partial albinism.... more
The Tyrosinase (TYR) gene produces an enzyme that is required for melanin production. The wild type allele C is dominant and causes full pigmentation, two mutations in TYR have been associated with temperature-sensitive pigment production that results in colors known as Burmese and Siamese. The wild type phenotype is full color. The Burmese phenotype, which is the mildest form of albinism, is characterized by a normal pigmentation of the extremities and a slight shading of normal body colour. The eyes are yellow-gray or yellow-green. The Siamese phenotype reduces pigment production to the points and the eyes are blue. The wild type (C) allele is dominant to Burmese (cb). Burmese is incompletely dominant to Siamese (cs); Burmese and Siamese heterozygotes (cb/cs) are intermediate in color (mink).These tests identify carriers of Burmese (also called sepia) and Siamese pointed coloration.