SERPINC1 and hyperinsulinemic hypoglycemia, familial, 4: There was also a significant association between antithrombin III deficiency and thrombocytopenia (antithrombin III deficiency, 24.8% [33 of 133]; no antithrombin III deficiency, 5.0% [8 of 159]; P = 1.94 × 10−6).