A 6-year-old boy has a long history of a hereditary bleeding disorder characterized by spontaneous nontraumatic hemorrhages into joint spaces, skeletal muscle, and mucous membranes. Laboratory studies reveal a normal prothrombin time, elevated partial thromboplastin time, very low factor VIII, normal factor X, normal factor XI, and normal platelet aggregation studies with ristocetin. Which of the following is the most likely diagnosis?

Question

Quizplus · Accepted Answer

The boy's symptoms and lab findings, including very low factor VIII and elevated partial thromboplastin time, are characteristic of hemophilia A.  Hemophilia A is a genetic disorder characterized by very low levels of factor VIII, elevated partial thromboplastin time, normal prothrombin time, normal platelet aggregation with ristocetin, and spontaneous hemorrhages into joints, soft tissues, and mucosal surfaces.

A 6-Year-Old Boy Has a Long History of a Hereditary