The Veterinary Genetics Laboratory at the University of California, Davis has announced that they now have available a DNA test for the dilute gene.

This test is useful to identify carriers of dilute and to determine the genetic type for young animals that may have yet to develop their adult coloration.

The dilute gene (Melanophilin or MLPH) causes clumping and uneven distribution of pigment granules in the hair shaft, producing dilution of all coat colors.

Dilute is an autosomal recessive trait which means that two copies of the dilute allele are needed to produce the phenotype. The basic cat colors affected by the dilute gene include:

• Black pigment is diluted to Blue
• Red is diluted to Cream.

In breeds that include more unusual color descriptions:

• Champagne is diluted to Platinum
• Honey is diluted to Fawn

The wild type allele is non-dilute. Some cat breeds are fixed for the wild type, such as Egyptian Mau and Singapura, while others are fixed for dilute such as Chartreux, Korat and Russian Blue. Most other breeds have both wild type and dilute alleles.

The results are reported as:

d/d	Two copies of dilute allele. Coat color is diluted.
D/d	One copy of dilute allele. Cat is a carrier of dilute.
D/D	Full color. Cat does not have the dilute allele.

For additional assistance from the Veterinary Genetics Laboratory call Customer Service Department at 530-752-2211 or email Cat-Service.