Naked foal syndrome (NFS) is an inherited disorder found in the Akhal-Teke breed and is characterized by hairlessness, abnormal teeth development, digestive disorders, persistent diarrhea, and laminitis-like problems.
Phenotype: Naked foal syndrome (NFS) is an inherited disorder found in the Akhal-Teke breed and is characterized by hairlessness, abnormal teeth development, digestive disorders, persistent diarrhea, and laminitis-like problems.
Mode of Inheritance: Autosomal recessive
Alleles: N = Normal/Unaffected, NFS = Naked foal syndrome
Breeds appropriate for testing: Akhal-Teke
Explanation of Results:
Horses with N/N genotype will not have naked foal syndrome and cannot transmit this naked foal syndrome variant to their offspring.
Horses with N/NFS genotype will not have naked foal syndrome, but are carriers. They may transmit this naked foal syndrome variant to 50% of their offspring. Matings between two carriers result in a 25% chance of producing an affected foal.
Horses with NFS/NFS genotype will have naked foal syndrome, a condition incompatible with life.
The molecular basis of the hairlessness or naked foal syndrome (NFS) in Akhal-Teke breed has been identified by researchers in Switzerland. NFS has been known in the breed since 1938. Primary signs of the defect are lack of body, mane, and tail hair, abnormal teeth development, digestive disorders, persistent diarrhea, and laminitis-like problems. NFS is always fatal with most foals dying within weeks of birth, although some have survived to two years of age.
NFS is inherited as an autosomal recessive trait, which means that two copies of the mutation are needed to produce the disease. Carriers of NFS (1 copy of the mutation) are normal but can produce affected foals if bred to another carrier. The mutation associated with NFS is located in the gene ST14 (c.388G>T) and results in a truncated version of the gene, likely causing the improper formation of the epidermal barrier and hair follicle development.
Testing for NFS can help breeders and owners identify carriers of NFS and select mating pairs accordingly to avoid producing affected foals. Matings between two carriers have a 25% chance of producing NFS foals. Given the small population size of the breed, and to avoid further reductions of the gene pool, mating between carriers and normal horses are acceptable as they will not result in NFS foals.
Bauer, A., Hiemesch, T., Jagannathan, V., Neuditschko, M., Bachmann, I., Rieder, S., Mikko, S., Penedo, M. C., Tarasova, N., Vitková, M., Sirtori, N., Roccabianca, P., Leeb, T., & Welle, M. M. (2017). A Nonsense Variant in the ST14 Gene in Akhal-Teke Horses with Naked Foal Syndrome. G3 (Bethesda), 7(4), 1315-1321. doi: 10.1534/g3.117.039511