Congenital macrothrombocytopenia (CKCS type) (CM)
Summary
Some Cavalier King Charles Spaniels (CKCSs) have an unusual feature in their blood known as congenital macrothrombocytopenia (CM). This means their blood has large platelets (clumping cells that help stop bleeding) that are fewer in number than in most other dogs. These large platelets still work normally and don't cause any bleeding problems for the dog. CM does not require treatment. However, CM can make it look like a serious bleeding disorder on a blood test.
You should tell your vet if your dog has the mutant form of the ?1-tubulin gene which causes CM to avoid misdiagnosis and unnecessary treatments. The result of this gene test may also inform your breeding choices.
CM requires two copies of the mutant ?1-tubulin gene, one from each parent, to develop in dogs. It affects both males and females equally. Carriers (with one copy) won't have CM but can pass the gene on to offspring.
Gene or region and technical reference
Gene: TUBB1 (causative). Reference: Davis et al. (2008)
Reported alleles
n. Test developed using artificial DNA, animal controls.
CM. Test developed using artificial DNA, animal cases.
Panels: groups of tests that are often ordered together
This test is in the CKCS health mini-panel.
