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Naked Foal Syndrome (NFS Horse)

Naked Foal Syndrome (NFS) refers to lethal hairlessness in Akhal-Teke horses. Affected foals have almost no hair and usually die shortly after birth. The disease is inherited in an autosomal recessively.


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  • Sparse coat (very little or no hair)
  • Ichthyosis (dry, thickened skin)

General Information

  • Naked Foal Syndrome (NFS) causes hairlessness in horses and early death of affected foals due to a variation in ST14 gene.
  • Affected horses usually die shortly after birth or before the age of 3 years.
  • The exact cause for the early death is not yet known.
  • NFS was first reported in 1938.

Breeds affected


Test Information

This test detects the change of a single basepair in the ST14 gene.


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Genotype and Lab Report

Inheritance: autosomal recessive

→ Only horses with two copies of the variant (nfs/nfs) are affected. Animals with only one copy (N/nfs) are clinically healthy carriers.




N/N = normal

The horse has no copies of the genetic variant causitive for NFS and therefore cannot pass it on to its offspring.


N/nfs = a carrier

The horse is clinically healthy.  It has one copy of the genetic variant causitive for NFS, which will be passed on to its offspring with a probability of 50%.


nfs/nfs = affected

The horse is affected and has two copies of the genetic variant causitive for NFS.  If the animal lives long enough to reproduce, the variant will be passed on to all offspring. All offspring will be carriers (N/nfs).


  • Carriers may be bred to normal animals (N/nfs x N/N) without any risk of producing affected offspring. The offspring should also be tested before breeding to determine if they are carriers or genetically normal.
  • Breeding two carriers (N/nfs x N/nfs) is not recommended due to the possibility of 25% of the offspring being affected.
  • Affected animals (nfs/nfs) should not be used for breeding.


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. : A Nonsense Variant in the ST14 Gene in Akhal-Teke Horses with Naked Foal Syndrome. G3 (Bethesda) 7:1315-1321, 2017.
Pubmed reference: 28235824. DOI: 10.1534/g3.117.039511.  


Further information is available at Online Mendelian Inheritance in Animals.

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