Dr. van Haeringen Laboratorium B.V.

P591 Coat Colour Dominant White 1


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.

White patterning in horses is known as Dominant White or White. Dominant White patterns are variable, ranging from minimal Sabino-like spotting to all-white horses. The eye colour of Dominant White horses is brown. There are about 20 different mutations identified that are associated with white patterns, all mutations are found in the KIT gene. Except for W20, most of the known Dominant White mutations arose recently and are restricted to specific lines within breeds. The Coat Colour Dominant White 1 test (P591) tests for the mutation known as W18 in the KIT gene. This test detects two variants (alleles). The allele W18 is dominant. One or two copies of the W18 allele result in horses that display some degree of white spotting but the specific pattern cannot be predicted. The allele N is recessive and does not have an effect on the basic colour.

Test specific information

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.

Breed dependence

This DNA test is available for the following breeds: Swiss Warmblood. 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, Hair, 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.

Code P591

Coat Colour Dominant White 1

€ 47,80 (Incl. 21% VAT)
€ 39,50 (Excl. VAT)