Genetics and Hemostatic Potential in Persons with Mild to Moderate Hemophilia A with a Discrepancy between One-Stage and Chromogenic FVIII Assays.

Background:  Factor VIII (FVIII) activity (FVIII:C) can be measured by different methods including one-stage clotting assays (OSAs) and chromogenic assays (CSAs). Discrepancy between FVIII:C assays is known and associated with genetic variations causing mild and moderate hemophilia A (HA). We aimed to study the discrepancy phenomenon and to identify associated genetic alterations.