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.
In each dog two pigments are the basis for their coat colour: black pigment (eumelanin) and red/yellow/cream pigment (pheomelanin). The production of black and red/yellow/cream pigment is controlled by the Melanocortin 1 Receptor (MC1R) gene, also known as Extension gene or E-Locus. The Coat Colour E-Locus (H734) and Coat Colour Em-Locus (H818) combined reveal the genetic status of the E-Locus.
The E-Locus has three variants (alleles). The Em allele is dominant over the alleles E and e; allele E is dominant over allele e. The dominant allele Em causes a melanistic face mask. Dogs that are solid black may have the allele Em but the mask is not visible as it is indistinguishable from the body colour. Dogs with white muzzles may have the allele Em but the mask is overridden by white spotting patterns. The Melanistic face mask is present in a variety of breeds (e.g. Afghans, Akitas, Boxers, French Bulldogs, German Shepherds, Great Danes, Greyhounds, Pug Dogs and Whippets). Pug Dogs and Boxers are fixed for the Em allele. The allele E results in a black coat colour and the allele e results in a red coat colour. In Afghan and Saluki hounds a fourth allele has been identified which only is expressed when the dominant black (K-Locus) is not present and the A-Locus is at/at. This fourth allele Eg causes a pattern that is called grizzle or domino. VHLGenetics does not offer a test that detects the Eg allele.
Test specific information
This test is also included in a Combination Package.
Since 2015, two brands have been developed. CombiGen® is mainly directed at veterinarian applications, whereas CombiBreed® is mainly directed at breeders and/or owners.
Detailed information about Coat Colours and Coat Variation is presented at www.combibreed.com.
Most coat colours and coat types are usually visible directly after birth.
Turn Around Time
The turn-around-time of a test depends to a large extent on the logistics of sample transportation to the laboratory. After receiving the sample at the test location, you can normally expect the result within 10 working days. A longer delivery time applies to tests carried out by a Partner Lab.
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.
For this test samples from all breeds are accepted.
For this DNA test we accept the following materials: Blood EDTA, Swab, Blood Heparin, Tissue, Semen. 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
Genetic characteristics are not a disease.