Mucopolysaccharidosis Type VII (MPS 7 Dog)
Mucopolysaccharidosis type VII (MPS VII) 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, corneal clouding and various heart problems.
The disease occurs in the German Shepherd Dog. The inheritance is autosomal recessive.
Symptoms
- Skeletal anomalies
- Dwarfism
- Corneal clouding
- Loss of muscle control and coordination
- Various heart problems
General Information
- Mucopolysaccharidosis type VII (MPS VII) 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
German Shepherd Dog
Test Information
This mutation test detects a change of a single base pair (c.497G>A) in the GUSB gene.
Genotype and Lab Report
Inheritance: autosomal recessive
→ The disease only occurs if both copies of the gene (mps7/mps7) are affected by the mutation. Dogs that have only one copy of the causative mutation (N/mps7) are clinically healthy carriers.
Genotypes:
N/N = genetically normal
The dog has no predisposition for MPS VII and therefore cannot pass it on to its offspring.
N/mps7 = a carrier
The dog is a clinically healthy carrier. The variation is passed on 50% to the offspring, which are also carriers.
mps7/mps7 = affected
The variation is passed on 100% to the offspring (if the animal is able to reproduce at all). The offspring are carriers or affected.
Recommendations
- Carrier animals can be bred to normal animals (N/mps7 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/mps7 x N/mps7) should be avoided because there is a 25% chance that the offspring will be affected.
- Affected animals (mps7/mps7) should be excluded from breeding.
Literature
Silverstein Dombrowski, DC., Carmichael, KP., Wang, P., O'Malley, TM., Haskins, ME., Giger, U.: Mucopolysaccharidosis type VII in a German Shepherd Dog.J Am Vet Med Assoc 224:553-7, 532-3, 2004. Pubmed reference: 14989549.
Further information is available at Online Mendelian Inheritance in Animals.