Mucopolysaccharidosis Type IIIA (MPS 3A Dog)
Mucopolysaccharidosis type IIIA (MPS 3A) is a lysosomal storage disease of the dog in which metabolic products cannot be broken down, leading to severe problems of the cellular metabolism. The first symptoms are usually recognised directly after birth, such as dwarfism, skeletal anomalies, loss of muscle control and coordination as well as various heart problems.
The disease occurs in the Dachshund. The inheritance is autosomal recessive.
Symptoms
- Skeletal anomalies
- Dwarfism
- Loss of muscle control and coordination
- Corneal clouding
- Various heart problems
General Information
- Mucopolysaccharidosis type IIIA (MPS 3A) is a lysosomal storage disease.
- Mucopolysaccharides (metabolic products) cannot be broken down and accumulate in the lysosomes.
- This leads to disturbances of the cellular metabolism and has serious consequences for the animal.
- The first symptoms are usually recognised directly after birth.
- Affected animals usually have to be euthanised.
Breeds affected
Dachshund
Test Information
This mutation test detects a deletion of 3 base pairs (c.737-739delCCA) in the SGSH gene.
Genotype and Lab Report
Inheritance: autosomal recessive
→ The disease only occurs if both copies of the gene (mps3a/mps3a) are affected by the mutation. Dogs that have only one copy of the causative mutation (N/mps3a) are clinically healthy carriers.
Genotypes:
N/N = genetically normal
The dog has no predisposition for MPS IIIA and therefore cannot pass it on to its offspring.
N/mps3a = a carrier
The dog is a clinically healthy carrier. The variation is passed on 50% to the offspring, which are also carriers.
mps3a/mps3a = affected
The variation is passed on 100% to the offspring (as a rule the animal does not reach breeding age). The offspring are carriers or affected.
Recommendations
- Carrier animals can be bred to normal animals (N/mps3a x N/N). Before the offspring are used for breeding, it should be tested whether they are normal or carriers.
- Mating two carrier animals (N/mps3a x N/mps3a) should be avoided because there is a 25% chance that the offspring will be affected.
- Affected animals (mps3a/mps3a) should be excluded from breeding.
Literature
Aronovich, E.L., Carmichael, K.P., Morizono, H., Koutlas, I.G., Deanching, M., Hoganson, G., Fischer, A., Whitley, C.B.: Canine heparan sulfate sulfamidase and the molecular pathology underlying Sanfilippo syndrome type A in Dachshunds.Genomics 68:80-84, 2000. Pubmed reference: 10950929. DOI: 10.1006/geno.2000.6275.
Further information is available at Online Mendelian Inheritance in Animals.