Hair shaft dysplasia / hypotrichosis (DSG4-related) - Cat

Hair shaft dysplasia in cats

This genetic test examines two variants in DSG4 that cause hair shaft dysplasia in cats. The condition may also be described as hair shaft dysplasia, hair shaft defect or hypotrichosis. DSG4 encodes desmoglein 4, a protein needed for normal hair formation and strength.

Cats with two copies of a disease variant can develop abnormal hair structure. The coat may be thinner, shorter, more brittle or patchy. Because carriers usually do not show a clear visible coat problem, DNA testing is especially useful for identifying hidden carrier status.

What is tested?

• Type 1: the DSG4 variant c.76del.
• Type 2: the DSG4 variant c.1777del.

Practical value of this test

The result shows whether the cat carries zero, one or two copies of the tested DSG4 variant. This helps breeders plan matings more deliberately, avoid carrier x carrier combinations and prevent kittens affected by hair shaft dysplasia. In cats with an abnormal coat, the test can help confirm a targeted genetic explanation.

DSG4-related hair shaft dysplasia follows autosomal recessive inheritance. A cat with one copy is a carrier; a cat with two copies develops the related hair and coat phenotype.