Breeds Affected: Plott Hound
Samples Accepted: Blood, Buccal Swab
Disease Information: Mucopolysaccharidosis Type I (MPS I) is a lysosomal storage disease which leads to growth retardation, corneal clouding leading to visual impairment, and lameness due to problems with joints.
Inheritance Information: MPS I 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/mps1 The dog is a carrier, and can pass the allele on to approximately 50% of any offspring. If bred to another N/mps1 carrier, approximately 25% of the offspring will be normal, 50% will be carriers, and 25% will be affected.
mps1/mps1 The dog is affected. If bred to a normal animal, 100% of the offspring will be carriers. If bred to an N/mps1 carrier, 50% of the offspring will be carriers and 50% will be affected.
– Carriers may be bred to normal animals (N/mps1 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/mps1 x N/mps1) is not recommended due to the possibility of 25% of the offspring being affected.
– Affected animals (mps1/mps1) should not be used for breeding.
Test information: This mutation test identifies a single base change in the IDUA gene.
Menon, K.P., Tieu, P.T., Neufeld, E.F.: Architecture of the Canine IDUA Gene and Mutation Underlying Canine Mucopolysaccharidosis-I. Genomics 14:763-768, 1992. Pubmed reference: 1339393.
Further information is available at the Online Mendelian Inheritance in Animals website