Dr. van Haeringen Laboratorium B.V.

P904 Coat Colour Chestnut


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.

Each horse has a basic colour, which can be black, bay/brown or chestnut. These basic coat colours are controlled by the Extension and Agouti genes. The Extension gene (E-locus) controls the production of black and red pigment. The Coat Colour chestnut test (P904) tests for the genetic status of the Extension gene. The Extension gene has two variants (alleles). The dominant allele E produces black pigment and the recessive allele e produces red pigment. All horses, regardless of their coat colour do have the genetics for black or red pigment. Red horses (for example chestnut, sorrel, palomino and cremello) have two copies of the recessive allele e, also called homozygous ee. Black pigmented horses (for example black, bay, brown, smoky black, buckskin, smoky cream and perlino) have at least one copy of the allele E. They can be homozygous EE or heterozygous Ee.

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.

Breed dependence

For this test samples from all breeds are accepted.

Sample type

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.

Code P904

Coat Colour Chestnut

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