Thrombocytopenia in Cairn Terriers and Norfolk Terriers

Thrombocytopenia is a disorder of blood clotting, manifested by severe bleeding conditions. It is called macrotrombocytopenia, in which the platelets produced are larger, but their count is low.

In Cairn Terriers and Norfolk Terriers, the disease is caused by a missense mutation c.5G>A in the gene for β1-tubulin (TUBB1).

The mode of inheritance of the mutation is autosomal recessive. This means that only individuals who inherit the mutated gene from both parents will develop the disease. Carriers of the mutated gene are clinically healthy but pass the mutation on to their offspring. In the case of a mating between two heterozygous individuals, theoretically 25% of the offspring will be completely healthy, 50% of the offspring will be carriers and 25% of the offspring will inherit the mutated gene from both parents and will therefore be affected by the disease.

The genetic test can clearly reveal the genotype of the animal and is a useful tool for breeders to prevent unintentional breeding of affected puppies.

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References:

Gelain, M.E., Bertazzolo, W., Tutino, G., Pogliani, E., Cian, F., Boudreaux, M.K. : A novel point mutation in the β1-tubulin gene in asymptomatic macrothrombocytopenic Norfolk and Cairn Terriers. Vet Clin Pathol 43:317-21, 2014. Pubmed reference: 25060661.