Breeds Affected: New Zealand Huntaway Dog
Samples Accepted: Blood, Buccal Swab
Disease Information: Mucopolysaccharidosis Type IIIA is a lysosomal storage disease diagnosed in dogs at an average age of 1 – 2 years. Affected dogs experience a rapid decline in muscle control and coordination, and must be humanely euthanized due to disease progression.
Inheritance Information: MPS IIIA is autosomal recessive, meaning that animals with two copies of this allele will be affected. Animals with one copy of the gene will be clinically-normal carriers.
The possible genotypes are:
N/N The dog is normal, and cannot produce affected offspring.
N/mps3a The dog is a carrier, and can pass the allele on to approximately 50% of any offspring. If bred to another N/mps3a carrier, approximately 25% of the offspring will be normal, 50% will be carriers, and 25% will be affected.
mps3a/mps3a The dog is affected. If bred to a normal animal, 100% of the offspring will be carriers. If bred to an N/mps3a carrier, 50% of the offspring will be carriers and 50% will be affected.
– Carriers may be bred to normal animals (N/mps3a x N/N) without any risk of producing affected offspring. The offspring should be tested before breeding to determine if they are carriers or normal.
– Breeding two carriers (N/mps3a x N/mps3a) is not recommended due to the possibility of 25% of the offspring being affected.
– Affected animals (mps3a/mps3a) should not be used for breeding.
Test information: This mutation test identifies a single base change in the SGSH gene.
Yogalingam, G., Pollard, T., Gliddon, B., Jolly, R.D., Hopwood, J.J.: Identification of a mutation causing mucopolysaccharidosis type IIIA in New Zealand Huntaway dogs. Genomics 79:150-153, 2002. Pubmed reference: 11829484. DOI: 10.1006/geno.2002.6699.
Further information is available at the Online Mendelian Inheritance in Animals website.