Frequencies of different types of F8 and F9 DNA variants detected in hemophilia. Classification of DNA variants detected in males with severe hemophilia A (A), mild–moderate hemophilia A (B), severe hemophilia B (C), and mild–moderate hemophilia B (D). For both hemophilia A and B, structural and nonsense variants predominate in severe disease, whereas missense variants account for most variants detected in mild–moderate disease.