Congenital deficiency of alpha 2-plasmin inhibitor in three sisters

3 young Japanese sisters with congenital alpha 2-plasmin inhibitor (alpha 2-PI) deficiency are reported. They have mild umbilical bleeding and/or repeated prolonged bleeding after minor trauma, but rarely spontaneous bleedings. The most characteristic hemostatic findings were shortened whole blood clot lysis time and euglobulin lysis time. Activities of all hemostatic factors except alpha 2-PI were within normal range. Both functional and immunological absence of alpha 2-PI were found in the plasma, and this failure to detect alpha 2-PI was not corrected by the addition of the patient's plasma of the first described case of alpha 2-PI deficiency. Clinical and laboratory data revealed that these patients were probably homozygous for alpha 2-PI deficiency and born of heterozygous parents, but not of consanguineous ones. Bleeding episodes due to deficiency of alpha 2-PI in these patients were well controlled by an antifibrinolytic agent, tranexamic acid.