DNA testing & simple inherited disorders

 

What is a simple inherited disorder?

Simple inherited disorders occur from a mutation of a single gene and represent a significant proportion of the known inherited diseases in the dog. Dogs are usually tested for these conditions through a simple DNA test, either from a blood sample, or more commonly from a cheek (buccal) swab. The inheritance of these diseases is predictable, provided that the test results for both parents are known. Often individual breeds, or related breeds, will have a predisposition to a specific simple, single gene disorder, although even in predisposed breeds, the percentage of dogs affected by the disease is usually, but not always, very low. These diseases are most commonly tested for in purebred dogs by responsible breeders, but also occur in cross breeds and mixed breeds.

Which DNA tests are recommended for my breed?

Before breeding, check whether any simple inherited disorders affect your breed. Information on the tests that are recommended can be found on the Breed Information Centre on the Kennel Club website, or you may wish to contact your veterinary surgeon, breed club or your dog's breeder.  An extensive list of breed specific health tests, and which laboratories perform the analysis, can be found here.

How do I know if a dog has been DNA tested?

The Kennel Club's online health resource, Mate Select, allows you to search for health test results for any dog registered on the Kennel Club's Breed Register. Searching the database is easy and only requires the dog's registered name, registration number or stud book number. It will display any health screening test results received and recorded by the Kennel Club from any Official Kennel Club DNA testing schemes (see below for more information), or from the British Veterinary Association/Kennel Club (BVA/KC) health schemes.  Not all DNA test results are published on Mate Select, but you can find a limited list of DNA tests recorded by the Kennel Club.

Mate Select also allows you to calculate the degree of inbreeding, or Coefficient of Inbreeding (COI), for potential puppies that could be produced from a hypothetical mating.  For more information on inbreeding and its impact on health, please click here.

Breeding from DNA tested dogs

DNA health testing is one of many resources that can help dog breeders make good breeding decisions. Knowing the health status of your dog allows you to make breeding plans to avoid producing puppies with a specific genetic condition.

Most DNA tested dogs can be used responsibly in a breeding programme, but the decisions you make when choosing which dogs to mate must be informed and carefully planned.  For information on how to breed responsibly from a clear, carrier or affected dog, please see the Breeding from your DNA tested dogsection of our Breeding for Health information guide.

How is DNA testing carried out?

Some tests require a small blood sample, which needs to be drawn by a qualified person, but increasingly these DNA tests are based on a simple mouth swab that is totally non-invasive and can be performed by the dog's owner. A small brush is used to gently rub the inside of the dog's cheek. The loose cheek cells that this removes stick to the bristles of the brush, which is then dried and returned to the laboratory. The cheek cells are broken open to liberate their DNA, which is produced in sufficient amounts to allow the genetic status of any dog to be determined.

What is an Official Kennel Club DNA Testing Scheme?

These testing schemes involve collaboration between the Kennel Club, the Breed Clubs and the DNA testing facility. Under any one of these schemes, the breeder/owner agrees for the result of their tested dog to be sent independently to the Kennel Club by the testing laboratory. The Kennel Club then notes the result on the dog's record in the registration database, and is published:

  • In the next available Breed Records Supplement
  • On any new registration certificate issued for the dog
  • On the registration certificates of any future progeny of the dog
  • On the Health Test Results Finder in the Kennel Club's online health rescource, Mate Select

The DNA tests used in these schemes can accurately identify clear, carrier and affected dogs, and can be used by breeders to effectively eliminate undesirable disease genes in their stock.  By publishing these results, it allows breeders to have a better understanding of which genes a dog may pass on to its offspring, giving them the information required to avoid producing affected puppies. Making informed decisions from health test results enables breeders to adapt their breeding programmes and reduce the risk of this disease appearing in future generations. 

A list of breed specific official Kennel Club DNA testing schemes and dogs tested under these schemes can be found here.

The Kennel Club is happy to consider a club's request to add a new DNA test to its lists and would normally need a formal request from the breed's Breed Health Co-ordinator or a majority request from the breed clubs. In most cases, the test would need to be run by a laboratory already recognised by the Kennel Club. All DNA tests must be able to record a definitive result for an individual dog, and must be based on robust science. The Kennel Club continues to work alongside breed clubs, breed health coordinators, and canine health professionals in a collaborative effort to improve the health of pedigree dogs.

DNA Control Schemes to eradicate genetic diseases

Some official DNA testing schemes have evolved into DNA control schemes, usually after several years of operation. A DNA control scheme links DNA testing to registration, limiting registration to those dogs that meet the requirements of the breed-specific DNA control scheme.

For example, in 2000, a DNA test was provided to Irish Setter breeders in the UK which allowed them to assess the genetic status of their dogs with regard to an inherited disease known as Canine Leucocyte Adhesion Deficiency (CLAD). Following consultation with the Irish Setter breed clubs, an official DNA testing scheme was established. During the next five years over a thousand Irish Setters were DNA tested and breeder selections based on these results were so successful that a DNA control scheme was introduced in 2005, meaning that the Kennel Club would only register Irish Setter litters from parents that were either DNA tested normal or were hereditarily clear. As a result of the DNA control scheme and the hard work of the breeders and breed clubs, CLAD has now been eradicated from the UK Irish Setter population.

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