Hemophilia B (Airedale Terrier Type)
Affected Genes: F9
Inheritance: Autosomal Recessive
Variant(canFam6):
chrX:95359344-95359345 5000 bp insertion
Breed: Airedale Terrier
General Information: Hemophilia B (Airedale Terrier Type) is an inherited bleeding disorder in dogs caused by a deficiency of clotting factor IX. This condition can lead to excessive bleeding from minor injuries, spontaneous bleeding into joints and muscles, and prolonged bleeding after surgery or trauma. Dogs with Hemophilia B have a mutation in the F9 gene, which encodes clotting factor IX, essential for normal blood coagulation. Symptoms may vary from mild to severe and can include prolonged bleeding after vaccinations or surgery, hematomas, nosebleeds, and blood in the urine or stool. Severe cases can lead to life-threatening hemorrhages. Early diagnosis and management, including clotting factor replacement therapy, are crucial for affected dogs to prevent serious bleeding episodes.
How to Read Your Dog's Test Results for this Genetic Variant:
Two Variants Detected: Dog Likely Affected
One Variant Detected: Dog Likely Carrier
No Variants Detected: No Effect
Gene / Testing Information: Genetic testing for Hemophilia B (Airedale Terrier Type) can determine if a dog carries the mutation in the F9 gene responsible for this condition. Hemophilia B is inherited in an X-Linked Recessive manner, meaning that males (with one X chromosome) are more likely to be affected if they inherit the mutation, while females (with two X chromosomes) are typically carriers if they inherit one copy of the mutation. Carrier females may pass the gene to their offspring, with male puppies having a 50% chance of being affected and female puppies having a 50% chance of being carriers. Accurate genetic testing is essential for responsible breeding practices to prevent the spread of this mutation. Breeding carrier females to unaffected males can prevent the birth of affected male puppies. Dogs that test negative for the mutation do not carry the gene and have no increased risk of producing affected offspring.
References:
Brooks, M. B., Gu, W., Barnas, J. L., Ray, J., & Ray, K. A Line 1 insertion in the Factor IX gene segregates with mild hemophilia B in dogs. Mammalian Genome 2003 14(11):788–795.
Gu, W., Brooks, M., Catalfamo, J., Ray, J., & Ray, K. Two distinct mutations cause severe hemophilia B in two unrelated canine pedigrees. Thrombosis and Haemostasis 1999 82(4):1270–1275.
Evans, J. P., Brinkhous, K. M., Brayer, G. D., Reisner, H. M., & High, K. A. Canine hemophilia B resulting from a point mutation with unusual consequences. Proceedings of the National Academy of Sciences of the United States of America 1989 86(24):10095–10099.
Mauser, A. E., Whitlark, J., Whitney, K. M., & Lothrop, C. D. A deletion mutation causes hemophilia B in Lhasa Apso dogs. Blood 1996 88(9):3451–3455.
Mischke, R., Kühnlein, P., Kehl, A., Langbein-Detsch, I., Steudle, F., Schmid, A., … Müller, E. G244E in the canine factor IX gene leads to severe haemophilia B in Rhodesian Ridgebacks. Veterinary Journal 2011 187(1):113–118.