Severe factor X deficiency treated with heparin-added prothrombin complex concentrate

PTT. FX level was found to be 1%. The mother’s FX level was 55%, the father’s 75%, and the sister’s 66%. He was treated with heparin-added PCC (KASKADIL). The hematoma disappeared and afterwards he was kept in a prophylactical replacement schedule. On several vaccinations, bleeding has not been a problem. Using the formula [body weight (kilogram) � desired FX increase (%)]/ (1.5), his FX levels were raised to 50% before subsequent vaccinations. With this therapy, no further bleeding or thromboembolic complications due to PCC were recognized. FX deficiency occurs in fewer than one in 500,000 in the general population. FX is a glycoprotein of the intrinsic and extrinsic pathways of blood coagulation. It is a serine protease. The zymogene is activated by F-IXa or F-VIIa and converts prothrombin to thrombin [12]. The molecular genetics of FX deficiency include gene deletions, dysfunctional variants and variants that affect synthesis or function of FX [12]. A report of an Italian family with factor X deficiency showed a partial and heterozygous gene deletion, causing a defect of FX antigen and activity [12]. Although no genetic investigation is carried out in our case, the near normal FX levels of the parents supposed variations of genetic defects, but bimodal distribution of normal variants of FX cannot be excluded.