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.
Roan is a white patterning coat colour trait of intermixed white and coloured hairs in the body while the head, lower legs, mane and tail remain colored. Roan horses are born with the pattern, though it may not be obvious until the foal coat is shed. The white and coloured hairs are evenly mixed in horses that inherit the classic Roan gene, which can differentiate this from several mimic patterns called roaning. Roaning patterns tend to be uneven in the distribution of white hairs and the inheritance of roaning has not been defined. The mutation causing the Roan coat colour has not yet been identified. The Coat Roan test (P659) tests for DNA markers that are associated with Roan coat colour in several breeds, the DNA markers can be used to determine if a horse has the Roan mutation and how many copies. This test detects three variants (alleles), Rn, Rn* and N. The allele Rn is dominant. One or two copies of the Rn allele result in a Roan coat colour. The allele Rn* is very uncommon and not always associated with the Roan coat colour, this allele has only been observed in Tennessee Walking horses and Rocky Mountain horses. The allele N is recessive and does not have an effect on the basic colour.
Test specific information
This test is performed by UCDavis.
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.
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.
For this test samples from all breeds are accepted.
For this DNA test we accept the following materials: Hair, Blood EDTA, Blood Heparin, Semen, Tissue. Please contact Dr. Van Haeringen Laboratorium if you wish to submit other material as listed.
Coat colours 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.