There are currently five genetic tests for genetic diseases know to exist in Quarter Horses and related breeds, including Appaloosas. It is unknown whether these five genetic conditions also exist in Australian Spotted Ponies. A&ASP Inc. believe that as a breed society, we should be leading the way in the eradication of these five genetic diseases within our breeds.
DOMINANT GENETIC DISEASES
Three of these genetic diseases, HYPP, PSSM1 and MH, are inherited in an autosomal dominant fashion. This means that if a horse has one copy of the disease allele, it has the genetic disease. This is illustrated below.
DOMINANT GENETIC DISEASES
Three of these genetic diseases, HYPP, PSSM1 and MH, are inherited in an autosomal dominant fashion. This means that if a horse has one copy of the disease allele, it has the genetic disease. This is illustrated below.
Individuals
which are homozygous affected (have two copies of the disease allele)
will always pass the genetic disease onto their progeny. Individuals
which are heterozygous affected have a 50% chance of passing the genetic
disease onto their progeny. To eliminate these diseases from the gene
pool, only those animals which are unaffected (have no copies of the disease allele) should be bred forward.
Hyperkalemic periodic paralysis (HYPP) - The mutation causing HYPP causes affected individuals to have episodes of muscle spasms and/or paralysis. Some HYPP episodes have related in the death of the affected individual. To date, HYPP has only been confirmed in descendants of the American Quarter Horse stallion Impressive.
Polysaccharide Storage Myopathy Type 1 (PSSM1) - PSSM1
Malignant hyperthermia (MH) - MH
RECESSIVE GENETIC DISEASES
Two of the genetic diseases, HERDA and GBED, are inherited in an autosomal recessive fashion. This means that the horse must have two copies of the disease allele to have the genetic disease. This is illustrated below.
Hyperkalemic periodic paralysis (HYPP) - The mutation causing HYPP causes affected individuals to have episodes of muscle spasms and/or paralysis. Some HYPP episodes have related in the death of the affected individual. To date, HYPP has only been confirmed in descendants of the American Quarter Horse stallion Impressive.
Polysaccharide Storage Myopathy Type 1 (PSSM1) - PSSM1
Malignant hyperthermia (MH) - MH
RECESSIVE GENETIC DISEASES
Two of the genetic diseases, HERDA and GBED, are inherited in an autosomal recessive fashion. This means that the horse must have two copies of the disease allele to have the genetic disease. This is illustrated below.
Affected individuals should not be breed. If a horse only has one copy
of the disease allele (and one copy of the normal allele), it is known
as a carrier. Carriers do not have the genetic disease, but they can
pass the genetic disease onto their progeny if mated with another
carrier. For this reason carrier x carrier matings
should be avoided. Carrier x homozygous dominant matings will not produce affected
progeny.
Hereditary equine regional dermal asthenia (HERDA) - The
Glycogen Branching Enzyme Deficiency (GBED) - The
TESTING
A&ASP Inc. has a genetic testing
NEW A&ASP Inc. POLICY REGARDING GENETIC DISEASES
Any animal registered in Category A, Category B or Category H after June 2016 MUST be tested for all five genetic disorders PRIOR TO BEING BREED.
Remove affected (Category C)
Carriers allowed but MUST NOT BE BREED to other known carriers.
Genetic test results will be included on the horses registration papers
Clear by parentage
A&ASP Inc. will not register any new animals known to be affected Hereditary equine regional dermal asthenia GBED
TESTING
NEW A&ASP Inc. POLICY REGARDING GENETIC DISEASES
Any animal registered in Category A, Category B or Category H after June 2016 MUST be tested for all five genetic disorders PRIOR TO BEING BREED.
Remove affected (Category C)
Carriers allowed but MUST NOT BE BREED to other known carriers.
Genetic test results will be included on the horses registration papers
Clear by parentage
A&ASP Inc. will not register any new animals known to be affected
Glycogen Branching Enzyme Deficiency (GBED) - The
TESTING
A&ASP Inc. has a genetic testing
NEW A&ASP Inc. POLICY REGARDING GENETIC DISEASES
Any animal registered in Category A, Category B or Category H after June 2016 MUST be tested for all five genetic disorders PRIOR TO BEING BREED.
Remove affected (Category C)
Carriers allowed but MUST NOT BE BREED to other known carriers.
Genetic test results will be included on the horses registration papers
Clear by parentage
A&ASP Inc. will not register any new animals known to be affected Hereditary equine regional dermal asthenia GBED
TESTING
NEW A&ASP Inc. POLICY REGARDING GENETIC DISEASES
Any animal registered in Category A, Category B or Category H after June 2016 MUST be tested for all five genetic disorders PRIOR TO BEING BREED.
Remove affected (Category C)
Carriers allowed but MUST NOT BE BREED to other known carriers.
Genetic test results will be included on the horses registration papers
Clear by parentage
A&ASP Inc. will not register any new animals known to be affected
