Curly Coat/Hairless Coat – Devon Rex and Sphynx

In cats, the growth and structure of coat hairs is partially governed by the gene for keratin 71 (KRT71). Mutations to KRT71 can result in several different curled coats, known as “rexoid”, and even in the hairlessness of the Sphynx breed.

The mutation responsible for the Sphynx’s distinctive lack of hair is designated as “hr”. The mutation is recessive to the wild-type (which results in normal hair growth), but is dominant over the mutation “re”, which causes the Devon Rex curly-coat mutation.

Cats affected by the hr mutation develop abnormal hair shafts, which results in a complete or nearly-complete lack of hair across the body. The cat’s whiskers may be short and broken, or likewise missing entirely. Without a protective layer of fur, affected cats are more sensitive to temperature extremes, and more susceptible to yeast infections of the skin.

The Devon Rex signature coat, caused by the re mutation, is short, wavy and sparse, with little shedding. The mutation results in hairs that are relatively thin and fragile, making affected cats somewhat prone to developing bald patches from intensive grooming.

The mutation in this test does not provide insight on the cause of hairlessness in the Don Sphynx and related cats, which are not genetically related to the 'regular' Sphynx (Canadian Sphynx).

Pubmed ID:

Year published:

Omia ID: 1581; 1583