A Case of Factor X Deficiency

Abstract

This is a case report on 38-year-old Japanese male diagnosed as having a congenital Factor X deficiency at our clinic.
He was hospitalized because of gross hematuria of one week duration.
The patient gave a past history of hematuria on several occasions since childhood and abnormal bleeding at the time of surgical procedure at age 13. He also experienced intramuscular hematoma after strenuous exercise at age 17.
Routine coagulation studies revealed prolonged prothrombin time and activated partial thromboplastin time. Platelet count, vascular fragility test and fibrinolytic system were within normal limits. Coagulation factors were normal except for the factor X. Activies of factor X were 2.4% by Quick one-stage method and 0.84% by Stypvencephalin cotting time.
In addition to these factor X assay, both chemical determination using synthetic chromogenic substrate (S-2222) and radioimmunoassay revealed extreme low factor X level. The former showed 0.5% and the latter showed 1.18 μg/ml.
These results were thought to indicate a classical factor X deficiency.
Further analytical study on the patient's family members revealed that the levels of factor X were 41%, 40%, 45% and 45% on father, mother, son and daughter of the patient respectively.
The parents are not consanguineous. Both parents and patient's children are asymptomatic heterozygotes.
Congenital factor X deficiency is a rare disease. Only 6 cases has been reported in Japan since the first report described in 1964. These cases are reviewed and discussed in this paper.