Mucopolysaccharidosis IIIA (New Zealand Huntaway Type)

General Information: Mucopolysaccharidosis IIIA (MPS IIIA) in New Zealand Huntaways is a severe inherited lysosomal storage disorder. This condition is caused by a deficiency in the enzyme heparan N-sulfatase, which is necessary for breaking down heparan sulfate, a crucial component of connective tissue. Without this enzyme, heparan sulfate accumulates in cells, particularly in the nervous system, leading to progressive neurological damage. Affected dogs typically begin to show symptoms around 18 months of age, including ataxia (loss of coordination), loss of learned behavior, and general neurological decline. Unlike other types of mucopolysaccharidosis, MPS IIIA in New Zealand Huntaways primarily affects the nervous system with minimal involvement of joints and other organs. The disease progresses rapidly, and affected dogs often face severe neurological deterioration, leading to euthanasia within a month of the onset of symptoms due to poor quality of life.

How to Read Your Dog's Test Results for this Genetic Variant:

Two Variants Detected: Dog Likely Affected

One Variant Detected: Dog Unlikely Affected

No Variants Detected: No Effect

Gene / Testing Information: Genetic testing of the SGSH gene can determine whether a New Zealand Huntaway is a carrier of mucopolysaccharidosis IIIA (New Zealand Huntaway Type). This condition is inherited in an autosomal recessive manner, meaning a dog must inherit two copies of the mutated gene, one from each parent, to develop the disease. Carrier dogs, possessing only one copy of the mutation, typically do not exhibit symptoms but can pass the defective gene to their offspring. When two carriers are bred, there is a 25% chance of each puppy inheriting the disease and a 50% chance of each puppy being a carrier of the SGSH gene mutation. Conducting reliable genetic testing is crucial for responsible breeding practices to prevent breeding two carriers together and thus reduce the risk of producing affected puppies. It's important to note that while testing for the SGSH mutation is a key step in managing this condition, other genetic or environmental factors could contribute to similar neurological conditions, making comprehensive genetic screening essential.