Congenital Macrothrombocytopenia (Cairn and Norfolk Terrier Type)

General Information: Congenital Macrothrombocytopenia is an inherited blood disorder commonly found in Cairn and Norfolk Terriers, marked by the presence of abnormally large platelets, known as macroplatelets, and a lower than normal platelet count (thrombocytopenia). Despite these abnormalities, the macroplatelets function normally, and affected dogs usually do not show any clinical symptoms related to this condition. It is important to recognize this genetic condition because it can complicate blood tests; some automated analyzers may mistake macroplatelets for red blood cells, leading to inaccurate platelet counts and misdiagnoses. Affected dogs do not have an increased risk of bleeding, and their blood clotting times remain normal. The identification of macrothrombocytopenia is typically done through microscopic examination of a blood smear, which reveals the characteristic large platelets. While this condition itself does not pose a health threat, understanding it is crucial for accurate diagnosis and management of other potential blood-related issues.

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 the TUBB1 gene is essential to determine whether a dog is a carrier of the Congenital Macrothrombocytopenia (Cairn and Norfolk Terrier Type) mutation. 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 be affected. Dogs carrying only one copy of the mutation typically do not show any symptoms but can pass the gene to their offspring. When two carriers are bred, each puppy has a 25% chance of being affected by the condition and a 50% chance of being a carrier. Accurate genetic testing is crucial for responsible breeding practices to avoid mating two carriers and to prevent the birth of puppies with this blood disorder. By ensuring that only non-carrier dogs are bred, breeders can help eliminate this condition from Cairn and Norfolk Terrier lines, promoting healthier generations and maintaining the integrity of breeding programs.