Newer approaches to the study of hemophilia and hemophilioid states.

Recent studies have shown that hemophilia, even if severe and classical in type, may be easily confused with other hemorrhagic states. Severe hemorrhagic manifestations, including repeated hemarthroses, a family history suggesting a sex-linked recessive inheritance, and laboratory findings, such as a long clotting time, normal prothrombin time, and delayed prothrombin utilization, may all be present; yet the disease may not be true hemophilia. On the other hand, it has been shown that hemophilia may be so mild that the diagnostic procedures in common use are inadequate for diagnosis. In the last fewyears many cases of hemophilia-like disease, different from either the severe or mild forms of hemophilia, have been described. As in hemophilia, there is a bleeding tendency from childhood, and often there are other bleeders in the family. The clotting defects shown by these patients are of several different types. They resemble hemophilia in that there is ineffectual conversion