Hypomyelination (Weimaraner Type)

General Information: Hypomyelination (HYM) (Weimaraner Type) is a genetic neurological disorder that affects dogs, causing a deficiency in the formation of myelin, the protective sheath around nerve fibers. Affected puppies typically develop generalized tremors between 1 to 3 weeks of age. These tremors, which are absent when the puppies are at rest or asleep, can cause a hopping gait in the hind limbs. The severity of the tremors can vary, even among littermates. While the tremors often improve by 3 to 4 months of age, some puppies may continue to exhibit a fine tremor in the hind limbs as they age. In severe cases, affected puppies may be euthanized within the first few weeks of life 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 for Hypomyelination (HYM) (Weimaraner Type) involves screening for mutations in the FNIP2 gene to determine carrier status. This disorder 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. Carriers of the gene mutation do not typically show symptoms but can pass the mutation to their offspring. When two carriers are bred, each puppy has a 25% chance of being affected and a 50% chance of being a carrier. To prevent producing affected puppies and eliminate the mutation from breeding lines, it is crucial to avoid breeding two carriers. Genetic testing is essential for responsible breeding practices, ensuring that dogs that are not carriers of the mutation do not pose a risk of producing affected puppies.