Prothrombin Quick. A newly identified dysprothrombinemia

The rarest of reported inherited plasmatic coagulopathies involve prothrombin. Only 10 families with significant reductions of this plasma protein (hypoprothrombinemia) have been observed. Even fewer, six families, have been found to have a functionally abnormal prothrombin (dysprothrombinemia) in their blood. An as yet undefined prothrombin abnormally has been recognized in eight other families. One of the first patients previously identified by Quick and his associates as having a defect in her plasma prothrombin has been shown to have about half the normal amount of prothrombin antigen but virtually no prothrombic function. We propose that this dysprothrombin be designated prothrombin Quick. An additional patient also first described by Quick was found to be truly hypoprothrombinemic--that is, to lack both functional and antigenic prothrombin. Briefly summarized are the other five families with dysprothrombinemia, nine with hypoprothrombinemia, and the eight in whom the defect has not been classified.