FAMILIAL ANTI-THROMBIN III DEFICIENCY IN A JAPANESE FAMILY

Familial antithrombin III (AT III) deficiency was found in Japanese family. The propositus (38 yr old female) had history of venous thrombosis of the left lower leg at 29 yr old, thrombotic varicophlebitis of the left lower leg at 33 yr old, and mesenteric venous thrombosis at 34 yr old. Laboratory examinations were in normal range except hyperaggregability of platelets and AT III, which was depressed in both immunological and biological measurement. This is the first case where AT III deficiency and hyperaggregation of platelet in platelet-rich plasma level were observed. The immunological AT III concentration was also depressed in her mother, brother and son. However, their biological AT III activity did not parallel that of the immunological activity. This discrepancy is the reverse type of AT III Budapest". © 1979."