Policy for Genetic Disorders

The ATA Board of Trustees unanimously approved a policy dealing with Arabian genetic disorders in the Trakehner breed at the 2012 annual board meeting. In addition, the membership voted on November 3, 2012 to amend the ATA’s corporate regulations to prevent further introduction of known mutational disorders into the Trakehner breed.

The specific genetic disorders we are currently confronting are Cerebellar Abiotrophy (CA), Severe Combined Immunodeficiency Syndrome (SCID), and Lavender Foal Syndrome (LFS), all recessive genetic diseases endemic in the Arabian breed. New and 100% accurate DNA tests requiring only hair follicles are available for all three disorders. NOTE: If a hair sample is on file in the US with UC Davis (from previous genetic testing) it is not necessary to send an additional hair sample.

The Trakehner breed has used Arabian genetics for many decades. The great majority of highly successful Trakehner performance horses have Arabian influence in their pedigrees; and the possibility exists of these mutations being present in the carrier state in their descendants, although the incidence is expected to be low. But all three of these disorders have severe and heartbreaking results in foals that happen to inherit the same mutation from both parents.

The following policy gives everyone a chance to inexpensively test our breeding stock and eventually to virtually eliminate the mutations. Voluntary testing compliance is needed from our breeders to get the maximum benefit from the plan. The policy also requires all future stallions and some Arabian-descended mares to be tested before studbook entry.

ATA Policy on the Genetic Disorders of CA, SCID and LFS

1. The ATA recommends voluntary testing for CA, SCID, and LFS by owners of all currently-approved stallions. Of immediate importance are those current stallions with an Arabian, Anglo-Arabian, or Shagya-Arabian ancestor within the first three generations of their pedigrees.
2. The ATA recommends voluntary testing for CA, SCID, and LFS by owners of mares that are Arabians, Anglo-Arabians or Shagya-Arabians or that have an Arabian, Anglo-Arabian or Shagya-Arabian ancestor within the first three generations of their pedigrees.
3. Effective November 3, 2012, before entering the Official Stud Book, ALL newly approved stallions must be DNA tested through the ATA’s certified process to verify that they are not carriers of CA, SCID, or LFS, unless their parents have both tested negative for all three mutations by the ATA’s certified process.
4. Effective November 3, 2012, before entering the Official Studbook or Preliminary Studbook, all mares that are Arabians, Anglo-Arabians or Shagya-Arabians, or mares that have an Arabian, Anglo-Arabian or Shagya-Arabian ancestor within the first three generations of their pedigrees, must be tested through the ATA’s certified system to verify that they are not carriers of CA, SCID, and LFS unless their parents have both tested negative for these three mutations, by the certified system the ATA has established for this purpose.
5. All imported, approved Trakehner stallions and all imported mares that are Arabians, Anglo-Arabians, or Shagya-Arabian, or that have an Arabian, Anglo-Arabian or Shagya-Arabian ancestor within the first three generations of their pedigrees, must test negative for the three genetic mutations before registration in the ATA’s OSB or PSB.
6. Any Trakehner stallion or mare currently in the OSB or PSB that is proven to be a carrier of these genetic disorders would not have its approval revoked. Offspring of carrier parents however must test negative to be eligible for entry into the OSB or PSB.
7. The ATA office will serve as the required clearing house for genetic testing that will be accepted for this policy, including the receiving of hair follicle samples, submission to laboratories of the samples for genetic testing as well as confirmation of horse identity. This is the only way that the ATA can publish certified “clear” results, that is, certify that the results of mutation testing are applied to the right horse and the right pedigree. Results from hair samples submitted directly to labs cannot be accepted, for this reason.

Summary Discussion

The ATA has instituted these policies as part of its stated mission to preserve the breed. The probability that any individual Trakehner horse is a carrier of any these genetic disorders is expected to be quite low.

Confirmation by certified “clear” testing will provide comfort and confidence to all breeders that they will not pass these disorders into future generations. If we test all our breeding stock now, eventually the testing will not be needed, except for imported Trakehner horses and Arabian horses applying for breeding approval in the ATA.

Horses that prove to be carriers are themselves in no way affected by these diseases and will have normal lives and riding horse career potential. We simply believe that they should not be used for breeding, because of the risk of crossing to another carrier, which can result in an affected foal.

The process of testing is very easy. All genetic testing is at the owner’s expense. The current fee for members for the complete panel, which must be paid to the ATA is $216. Non-members who wish to have horses tested pay double the member rate.

January 15, 2013