Red factor

Characteristic and trait of inheritance

The extension (E) locus determines the red factor (colour: chestnut, sorrel, ...). The dominant allele at this locus (E) leads to the expression of the pigment Eumelanin and the colour brown or black develops. If a horse is homozygous for the recessive form of this allele (e/e), Pheomelanin is synthesized and this horse will be red. A horse that is heterozygous at the E-locus (E/e) will be either black or brown depending on the Agouti-locus.
If a horse is homozygous (e/e) for the mutation, it will be red and all of its offspring will receive the mutated form of the gene (e). If such a horse is bred to a horse that does not carry the mutation (E/E), no red colour will result. Offspring with genotype E/e carries the mutation for red colour but is not red himself. If two carrier horses (E/e) are bred, red coloured offspring can result. If a non-carrier horse (E/E) is bred, its offspring will never be red coloured, even if the pairing is with a genetic carrier (E/e). However, such a pairing will result in 50% carriers (E/e) for the mutation.


All breed

Test duration

3-5 days after arrival of the sample in the lab


The DNA test is performed out of EDTA blood or or 20-30 hair roots from mane or tail. Test kits can be ordered free of charge. (order-form). If hair is sent in, possibly the genetic material is not sufficient to run the test. In this case it would be best to send in an EDTA blood sample.

Testing procedure

Please send in your sample together with the lab order genetic. Results will be transmitted optionally via post, fax or email. After completion of the test you will receive a separate invoice. Payment can be made via credit card or bank transfer.
Breeding club discounts apply if a copy of the membership card is sent together with the respective samples. Due to administrative reasons the invoiced price can not be altered subsequently.


Please contact our molecular biology team for further questions.

Steubenstraße 4
D-97688 Bad Kissingen

Telefon: +49 (0)971 72020
Fax: +49 (0)971 68546


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