Dr. van Haeringen Laboratorium B.V.

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H897 Coat Colour D-Locus (MLPH) 3


During the last decades, a large number of scientific publications have described the genetic principles of coat colour and coat variation. Coat colours and coat variations are influenced by many hereditary factors. The DNA-tests are based on physiological effects in the body, in which the production and distribution of pigments result in many coat colour variants. In several cases, the coat colour of an animal may only be decided using DNA-tests. The dilute gene (MLPH gene) is responsible for the intensity of the coat colour by affecting the distribution of melanin-containing cells. This gene is also known as the D-Locus and dilutes all colours. Besides the hair colour also the colour of the nose is diluted and the colour of the eyes lightens to amber.

The variant was denoted d3 in order to differentiate it from the formerly detected variant d, now called d1 and d2. The d3 allele is found at low frequency in multiple dog breeds, as well as in wolves, wolf-dog hybrids, and indigenous dogs. Canids in which the d3 allele contributed to the dilute (grey) phenotype were all either compound heterozygotes d1/d3 or homozygotes d3, whereas the non-dilute dogs carried at least one or two D alleles.

Test specific information



Most coat colours and coat types are usually visible directly after birth.

Turnaround time

The Turnaround Time (TAT) depends on various factors, such as the shipment time of your sample to the test location, the test method(s) and whether the tests are performed completely or partially by a Partner Lab or Patent owner.

The TAT of tests performed at our facilities is normally 10 working days after receipt of the sample at the testing laboratory (VHL, VHP or Certagen). For tests performed by a Partner Laboratory (so-called "partner lab test") or patent owner, the TAT is at least 20 working days after receipt of your sample. Because the shipment time to our Partner Labs or patent owner may vary due to factors we cannot influence, the mentioned 20 working days are therefore an estimate.

Sometimes it is necessary to re-run your sample. We call this a retest. In that case, the TAT will of course be extended.

Location of disease or trait

Genetic factors influencing coat colours and coat types are usually visible on the outside of an individual. Several factors may be hidden by the external variation.

Breed dependence

This DNA test is available for the following breeds: Chihuahua, Hungarian Puli, Italian Greyhound, Mudi, Pekingese, Sheltie, Shih Tzu, Tibetan Mastiff, Yorkshire Terrier. Additional information is available in the Frequently Asked Questions (FAQ).

Sample type

For this DNA test we accept the following materials: Blood EDTA, Blood Heparin, Semen, Swab, Tissue. Please contact Dr. Van Haeringen Laboratorium if you wish to submit other material as listed.


Coat colours and coat types are based on many genetic factors. For each factor, a separate test result will be returned.


Various genetic factors influencing coat colour and coat types are inherited in a dominant or recessive mode. Coat colours are influenced by a large number of genetic factors.

Severity of Disease

Factors influencing coat colour and coat types are usually not related to diseases.