Description:  PREVIOUS – LOCUS D. The locus D has two alleles D> d. Color dilution is inherited autosomal recessive, that is, recessive homozygous dd is able to dilute eumelanin (Drogemuller et al., 2007a). Black eumelanin is diluted to metallic blue or also called silver gray. Brown to red eumelanin is diluted to a creamy resulting phenotype called Isabella. To obtain complete information about locus D, we need to know the genotypes at loci E and B. The production of eumelanin or pheomelanin depends on the E allele. black or brown eumelanin. If a dog has the E_B_dd genotype, eumelanin will be diluted and the resulting phenotype will be metallic blue/silver-gray. If the dog has the genotype E_bbdd the resulting phenotype will be a cream color, Isabella (lilac).

Currently, 3 variants (alleles d1, d2, and d3) caused by three different mutations have been identified in locus D. The d1, d2, and d3 variants are analyzed separately (three different analyses).

Allele d1: c.-22G>A in MLPH gene

Allele d2: c.705G>C in MLPH gene

Allele d3: c.667_668insC in MLPH gene


Inheritance: autosomal recessive


Mutation: c.-22G>A in MLPH gene


Sample: EDTA whole blood (1.0 ml) or 2 buccal brushes. For official purposes, the confirmation of the dog’s identity by a Veterinarian is recommended.


The analysis is suitable for the following breeds: American Shepherd, mini American Shepherd, Australian Shepherd, mini Australian Shepherd, Briard, Doberman Pincher, Great Dane, German Pinscher, French Bulldog, Labrador Retriever, Large Munsterlander, Miniature Pincher, Newfoundland, Rhodesian Ridgeback,


Notes: Currently, alleles d1, d2, and d3 have been identified. Additional gene variants responsible for color dilution are expected to occur in other breeds.