A missense variant in the feline coagulation factor VIII gene, known as F8, has been identified in association with severe factor VIII deficiency and hemophilia A in both male and female domestic shorthair cats from a single household. This identification represents the first report of a coding sequence variant in feline F8 linked to severe hemophilia A
Hemophilia A is an X-linked recessive bleeding disorder that typically manifests in male individuals and is caused by deficiency or dysfunction of coagulation factor VIII. Although hemophilia A has previously been recognized in felines, earlier genetic analyses in cats were limited to the description of a non-coding variant in F8 in a single affected male
In the reported investigation, researchers conducted coagulation testing on a cohort of 19 domestic shorthair cats residing in a single household. Diagnostic evaluation identified seven cats with hemophilia A, established by coagulation factor VIII coagulant activity levels falling below 10 percent
The seven affected individuals comprised four male cats and three female cats. These animals exhibited severe factor VIII coagulant activity deficiency, recording a median activity value of 3 percent, along with significantly prolonged activated partial thromboplastin time relative to unaffected cats. Observed clinical manifestations included hematoma formatio