Heritable alpha 2-macroglobulin deficiency in a patient with arterial thrombosis: alpha 2-macroglobulin deficiency...

A heritable deficiency in α(2)-macroglobulin (α(2)M) was identified in a 61-year-old man with arterial thrombosis. Plasma α(2)M levels among the patient's symptom-free relatives consistently ranged from 43 to 55 percent of laboratory mean-normal values. The new α(2)M variant displayed retarded anodal immunoelectrophoretic mobility when studied in plasma and serum. The affected members of this lineage showed no evidence of acquired or inherited thrombotic or consumptive derangements involving other plasma proteins. The significance of a possible causal association between α(2)M deficiency and the predisposition to arterial thrombosis is considered. The uncomplicated use of streptokinase and urokinase to treat the reference patient's arterial thrombosis is described. Recommendations are made for the adoption of a descriptive nomenclature. The new familial deficiency is tentatively designated α(2) (+)-macroglobulin deficiency Irvine.