Abstract
Antithrombin III has been reported to be decreased in the cases of several thrombotic disorders and the decreased Antithrombin III is known to induce the hypercoagulable state. This study was started from the 28 year old male patient who developed the superior sagittal sinus thrombosis after appendectomy and it was followed by deep vein thrombosis of extremities. Antithrombin III level was 20.6mg/dl and activity was 68% by the progressive antithrombin assay and other laboratory examinations were within normal range excepts for the elevated serum lipids. Antithrombin III was assayed for his family members in three consecutive generations by single radial immunodiffusion method, coagulation assay, and chromogenic assay. Four out of 9 members were comfirmed to have low Antithrombin III level and activity ranging from 59-68% of normal values, although the two of these four members had no history of thrombosis. Mother of this propositus is deceised, but it was suspected of having the defect of Antithrombin III. History of peptic ulcers were found in all members of this family. The inheritance pattern of Antithrombin III deficiency was characteristic of an autosomal dominant disorder. Literature survey was performed on the previously reported deficient families and some discussions were made.
