D-Locus (Dilution)

The dilute gene (MLPH gene) is responsible for the intensity of the coat colour by affecting the amount of pigments in the hair shaft. This gene is also known as the D-locus and dilutes all colours. The Coat Colour Dilution test (K760) tests for the genetic status of the D-locus. The D-locus has two variants (alleles). The allele D is dominant and does not have an effect on the coat colour. Only when the cat has two copies of the recessive allele d the coat colour is diluted. The dilution of black results in grey, called blue by cat breeders. Chocolate/brown dilutes into lilac, it is described as dove or light taupe gray, and is sometimes called frost or lavender. Cinnamon dilutes into Fawn, it is described as “coffee and cream” or caramel color. Some cat breeds are fixed for one of the alleles. The Egyptian Mau and Singapura are fixed for the dominant allele D. The breeds Chartreux, Korat and Russian Blue are fixed for the recessive allele d. Most other breeds can have both alleles.

The Coat Colour Dilution test encloses the following results, in this scheme the results of the Coat Colour Dilution test are shown in combination with the possible results for the B-locus):