Glanzmann Thrombasthenia Type I
Heart/Blood • ITGA2B • Recessive
Summary
Glanzmann Thrombasthenia Type 1 (GT) is an inherited bleeding disorder first identified in Pyrenean Mountain Dogs (Great Pyrenees). It's caused by a mutation in the ITGA2B gene, which leads to a deficiency or dysfunction of the platelet membrane glycoprotein αIIb β3 (also known as the fibrinogen receptor). This autosomal recessive condition results in impaired platelet aggregation and clot formation, leading to excessive bleeding tendencies. The disorder affects the dog's ability to form stable blood clots, making them prone to prolonged bleeding episodes.
Symptoms
Dogs affected by GT typically show signs between 3 and 6 months of age. They often experience recurrent nosebleeds, which may continue until about 2 years of age. They are prone to easy bruising and may have prolonged bleeding after minor injuries. Surgical procedures or trauma can cause excessive bleeding that is difficult to control. Female dogs may experience prolonged bleeding during heat cycles. Affected dogs are also often smaller than the average for their breed.
Care
While there is no cure for GT, management focuses on supportive care and preventing bleeding episodes. Iron supplementation is often necessary to prevent deficiency, especially during growth or periods of chronic bleeding. Owners should avoid medications that affect blood clotting and inform vets about the condition before procedures. With proper management, affected dogs can have a good prognosis and a relatively normal lifespan. However, they require vigilant care and preparedness for potential bleeding emergencies.
Citations
Lipscomb, D.L., Bourne, C., Boudreaux, M.K. : Two genetic defects in alpha(IIb) are associated with type I Glanzmann's thrombasthenia in a Great Pyrenees dog: A 14-base insertion in exon 13 and a splicing defect of intron 13 Veterinary Pathology 37:581-588, 2000. Pubmed reference: 11105947.
Review
03/04/2026 by Dr. Margarette
Breed
Great pyrenees