Genetic test available for “naked foal” syndrome

Publish date:

Researchers have identified the gene responsible for a rare disease found primarily in Akhal-Teke horses, a breed native to Turkmenistan that is known for its glossy coat.

First described in 1938, “naked foal” syndrome (NFS) causes youngsters to be born nearly hairless. They typically die within weeks or months of birth, though the exact causes of death are still not fully understood.

Previous pedigree analysis revealed NFS to be an autosomal recessive trait, meaning a horse can carrya single copy of the gene without being affected, but when two such horses (called “carriers”) are mated, there is a 25 percent chance that the resulting foal will have the disease.

Seeking to develop a test to identify NFS carriers in the Akhal-Teke population, researchers at institutions across Europe, as well as at the University of California–Davis Veteri-nary Genetics Laboratory, worked together to analyze the genome of two affected horses, two carriers and 75 unaffected horses of other breeds.

Using the resulting data, the researchers identified a mutated gene on a chromosome associated with NFS, which enabled them to develop a genetic test. The analysis can show a horse to be free of the mutated gene, a carrier or “affected,” meaning he has inherited both copies of the mutated gene.

By using this test, Akhal-Teke breeders will be able to avoid breeding NFS carriers and reduce the number of affected foals produced. The test is now available through the UC–Davis laboratory.

This article first appeared in the May 2017 issue (#476) of EQUUS magazine