Recently, we observed a 13-year-old girl, the offspring of consanguinous parents, who exhibited a severe hemorrhagic diathesis. Laboratory studies revealed a prolonged bleeding time, normal platelet count, and poor prothrombin consumption. The thromboplastin-generation test and other assay procedures demonstrated a marked decrease in antihemophilic factor (AHF). A search of the literature suggested that this syndrome has been encountered by several investigators during the last two years.* So far we have been able to find 19 similar cases (14 females) in the literature, although most of the reports are rather fragmentary or of a preliminary nature.

This communication attempts to describe the clinical, hematologic, and genetic aspects of this disorder, which in our opinion represents a definite disease entity.

REPORT OF A CASEÌý A 13-year-old white Jewish girl was transferred to our department from another hospital for diagnosis and treatment of her severe hemorrhagic diathesis. She had had severe uterine bleeding