Further Studies on the Abnormal Factor X (Factor X Friuli) Coagulation Disorder: A Report of Another Family

Abstract

Another patient with a congenital coagulation disorder due to the presence of an abnormal factor X (factor X Friuli) is presented. The proposita was a 43-yr-old white female who had a bleeding tendency from early childhood (epistaxes, monorrhagias, bleeding after tooth extractions and other surgical procedures, posttraumatic hemarthroses, bleeding from the gums and postpartum hemorrhages). The coagulation work-up demonstrated a prolonged prothrombin time, prolonged partial thromboplastin time, abnormal prothrombin consumption, and abnormal thromboplastin generation corrected by normal serum. Factors II, V, VII, IX, and XII were within normal limits. Platelets, vascular tests and fibrinolysis were normal. Mr. Stuart’s plasma failed to correct the defect of the proposita’s plasma, but a known factor VII deficient plasma was able to correct the abnormality. The factor X assay was low (6-9%) only when tissue thromboplastin, whole or partial, was used. When Factor X was assayed with a Stypven-cephalin mixture, normal or near normal values were observed. Likewise, the Stypven-cephalin clotting time, the Stypven clotting time and the factor II + factor X level using a Stypven-cephalin mixture were normal. The presence of the abnormal factor X was demonstrated immunologically. The defect, like classical factor X deficiency, is transmitted as an autosomal incompletely recessive trait. The mother and the two children of our proposita had factor X levels varying from 38 to 56% of normal and were considered to be heterozygotes.

Prevalence of bleeding manifestations in 128 heterozygotes for Factor X deficiency, mainly for FX Friuli, matched versus 128 unaffected family members, during a long sequential observation period (23.5 years)

“…Factor X Friuli variant was first described by our group in 1970 (5,7). The bleeding defect was characterized by a prolonged aPTT and PT together with a normal RVV clotting time.…”

“…All heterozygote patients belonging to the families of the homozygote patients with FX deficiency seen in Padua during the years 1969-2010 are the subjects of this study (5)(6)(7)(14)(15)(16)(17)(18)(19)(20)(21)(22).…”

Congenital Factor X deficiency in women: A systematic review of the literature

“…13,14,16,17,22,24,26,28,36,40,48,59,60 The gestational age at delivery was not reported in three cases. 28,36,40 All of the term pregnancies resulted in live births (between 37 and 40 weeks); seven deliveries were by caesarean section 10,14,16,22,26,58,61 and nine by vaginal deliveries (use of forceps or vacuum was not repor ted). 8,13,24,28,36,40,48,59,60 Of preterm births, 3/8 (37.5%) resulted in neonatal death.…”

“…28,36,40 All of the term pregnancies resulted in live births (between 37 and 40 weeks); seven deliveries were by caesarean section 10,14,16,22,26,58,61 and nine by vaginal deliveries (use of forceps or vacuum was not repor ted). 8,13,24,28,36,40,48,59,60 Of preterm births, 3/8 (37.5%) resulted in neonatal death. 8,9 Gestational age at delivery for the preterm live births varied from 25 to 37 weeks.…”

“…Seventeen pregnancies did not receive any prophylaxis during the antenatal period [8][9][10]14,16,22,26,28,58,59 ; of these, two miscarried (one of these had FX level < 0.01 IU/mL, 8,9 seven cases were term live birth, 14,16,22,26,28,58,59 two live birth but gestational age at delivery was not mentioned (FX level 0.06 iu/ml in one case) 28 and six preterm deliveries (FX levels around 0.4 IU/mL). 9,10,58,61 Of the latter, two cases resulted in neonatal death (NND) [two spontaneous vaginal deliveries (SVDs) in the 2nd trimester and at 37 weeks, respectively].…”