Macrothrombocytopenia (MTC)

Macrothrombocytopenia (MTC) is an inherited (congenital) disorder in the formation of blood platelets (thrombocytes), which play an important role in blood coagulation. Symptom of hereditary MTC is a reduced number of platelets (thrombocytopenia). In addition, many of the remaining platelets are enlarged. Two causing variants have been identified in the ß1-tubulin gene. \nOne of the two mutations is inherited in an autosomal recessive manner. The platelet count of carrier animals does not differ from free animals. This variant has been found in the breeds Cairn Terrier, Norfolk Terrier. The other mutation is autosomal-dominant (intermediate), already one copy of the gene is sufficient to express an MTC. In heterozygous affected dogs the platelet count is between those of homozygous affected and free animals. This variant has so far been described in the following breeds: Bichon Frize, Boxer, Cavalier King Charles Spaniel, Chihuahua, Cocker Spaniel, Havanese, Jack Russell Terrier, Labrador Retriever, Maltese, Parson Russell Terrier, Poodle and Shih Tzu.\nAffected dogs are not prone to bleeding, but there is a risk of mistreatment, since the above signs can also be mistaken for acquired thrombocytopenia, which can be triggered by infections, medication or immune reactions, for example. The genetic test is therefore important as method of differential diagnosis, since antibiotics or corticosteroids are inappropriate to treat hereditary macrothrombocytopenia.\n