Recessive hypotrichosis / hairlessness (SGK3-related) - American Hairless Terrier

What does this test examine?

This genetic test examines the SGK3 variant c.287_290delTTAG in the American Hairless Terrier. The variant is associated with recessive hypotrichosis, also known as recessive hairlessness or congenital alopecia. The trait is inherited in an autosomal recessive manner: a dog is hairless when it carries two copies of the tested variant.

What does recessive hypotrichosis mean?

Affected puppies are usually born with a very thin, soft coat. During the first months of life this coat is largely or completely lost and does not regrow normally. This SGK3 form is different from dominant hairlessness in breeds such as the Chinese Crested and Xoloitzcuintle; in the American Hairless Terrier the recessive SGK3 allele is decisive and is not linked to the same dental and fertility problems known from the dominant FOXI3 form.

Practical value of this test

For breeders this test is highly useful because coated carriers and hairless dogs can be distinguished genetically. Breeding combinations can therefore be planned from genotype instead of relying only on appearance or pedigree.

• Confirms whether a dog is clear, a carrier, or carries two copies of the hairlessness allele.
• Helps predict whether offspring may be coated, carriers, or hairless.
• Supports careful preservation of genetic diversity in lines that include both coated and hairless dogs.
• Makes outcross and breeding decisions clearer without unintentionally losing or spreading the SGK3 allele.

Result and inheritance

A dog with N/N does not carry the tested variant. A dog with N/del is coated but carries the variant and can pass it on. A dog with del/del has the genotype that causes recessive hairlessness in the American Hairless Terrier.