Mucopolysaccharidosis IIIB (Schipperke Type)

General Information: Mucopolysaccharidosis IIIB (MPS IIIB) in Schipperkes is caused by a deficiency in the enzyme heparan N-sulfatase, crucial for breaking down heparan sulfate, a substance found throughout the body and especially in the nervous system. Symptoms usually emerge around the age of two and include neurological decline with notable signs like ataxia predominantly in the hind limbs, loss of reflexes, head tremors, swaying, and unusual eye movements. The accumulation of undegraded heparan sulfate leads to progressive damage particularly in neural tissues, resulting in severe mobility issues and quality of life deterioration. While the disease progression is typically slow, many affected dogs are euthanized within years of diagnosis due to declining neurological function.

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 for Mucopolysaccharidosis IIIB (MPS IIIB) in Schipperkes identifies mutations in the NAGLU gene, which is essential for making informed breeding decisions. MPS IIIB is transmitted through an autosomal recessive pattern, meaning that two copies of the mutated gene, one from each parent, are necessary for a dog to manifest the disease. Carriers of one mutant gene typically show no symptoms but can pass the mutant gene to their offspring. When two carriers are bred, each puppy has a 25% chance of being affected by MPS IIIB and a 50% chance of being a carrier. To prevent the transmission of this debilitating condition and to manage the breed's health, it is crucial not to breed carriers together. Testing is recommended before breeding to ensure neither parent carries the harmful mutation. Affected dogs, as well as carriers, can be identified reliably through genetic tests, helping to avoid the birth of affected puppies and maintain the overall health of future generations.