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 Tobiano coat pattern usually involves white on all four legs below the hocks and knees and rounded white spots on the body with sharp, clean edges. The head is dark, with white markings like those of a solid colored horse. The white on the body will generally cross the top-line of the horse. The skin underlying the white spots is pink and under the colored areas it is black. The eyes are usually brown, but one or both may be blue or partially blue. The tail can be two colors, a characteristic seldom seen in horses that are not tobiano. A horse can also carry mutations for other modifying genes which can further affect its coat colour.
The Coat Colour Tobiano test (P903) tests for a genetic factor that affects the function of the KIT gene. This gene has two variants (alleles). The dominant allele TO results in the Tobiano pattern and the recessive allele N does not have an effect on the basic colour.
Test specific information
This test is also included in a Combination Package Coat Colour.
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: Hair, Semen, Blood EDTA, Blood Heparin, 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 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.