Dr. van Haeringen Laboratorium B.V.

K304 Devon Rex, Curly Coat


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.

Two different mutations in the Keratin 71 (KRT71) gene influence the hair formation in Devon Rex and Sphynx cats resulting in a curly coat or a nearly hairless coat. The Devon Rex, Curly Coat (K304) and Sphynx, Hairless Coat (K305) tests combined reveal the genetic status of the KRT71 gene. The KRT71 gene has three variants (alleles). The N allele is dominant over the alleles hr and dr; allele hr is dominant over allele dr. The dominant allele N does not have an effect on the coat type. Two copies of the hr allele (homozygous hr/hr) or one copy of the hr allele in combination with one copy of the dr allele (heterozygous hr/dr) results in a nearly hairless coat. Two copies of the dr allele (dr/dr) results in a curly coat. For Sphynx breeders, the tests identify hairless cats that carry the curly mutation and therefore, depending on the mate, might get offspring with a curly coat.

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.


Symptoms will develop at a young age. Within a few hours to a maximum of several weeks after birth, the characteristics that go with these genetic effects will become visible.

Turnaround time

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.

Breed dependence

This DNA test is available for the following breeds: Devon Rex, Sphynx. 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, Swab, 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 K304

Devon Rex, Curly Coat

€ 57,48 (Incl. 21% VAT)
€ 47,50 (Excl. VAT)