Congenital deficiency of fibrin-stabilizing factor (factor XIII): a report of four cases (two families) and family members.

Four patients with congenital defiother family were found to have varyciency of fibrin-stabilizing factor (facing degrees of factor XIII deficiency. tor XIII) from two families have been The observations support the hypothedescribed. The mother and the sibs in sis of autosomal recessive inheritance one family and both parents in the of factor XIII deficiency. T HE EXISTENCE OF A BLOOD FACTOR that rendered clots prepared from purified fibrinogen insoluble in weak acid and urea was reported by Robbins’ in 1944. Laki and Lorand2 confirmed this observation in 1948 and designated this factor as the “fibrin-stabilizing factor.” In 1963, the International Committee on New Blood Clotting Factors accepted this entity as a distinct coagulation factor and gave it the designation factor XIII. Patients with factor XIII deficiency have a tendency to bleed and show poor wound healing. In these patients, the usual tests for blood coagulation give normal results except for a considerable degree of crumbling of the clot and a striking diminution of the amplitude of the thromboelastogram.3 The diagnosis is confirmed by the rapid dissolution of the clot obtained by recalcification of the plasma in a 5 M urea or a 1% monochioroacetic acid solution. The factor XIII deficiency has been documented in at least 44 individuals from 27 families,3 including a single case from Pakistan reported by Zahir4 from this laboratory. In this communication, four additional cases of bleeding disorders associated with the fibrin-stabilizing factor (factor XIII) deficiency from two families will be reported.