Congenital Haemorrhagic Condition Similar but Not Identical to Factor X Deficiency

Abstract

A 23‐year‐old white male with a bleeding tendency since early childhood presented a congenital coagulation defect similar but not identical to factor X deficiency. A first and second stage defect were demonstrated, characterized by a prolonged prothrombin time, prolonged partial thromboplastin time, abnormal thromboplastin generation, abnormal prothrombin consumption. The Stypven clotting time was slightly prolonged on fresh plasma but was normal on frozen plasma. Factors I, II, V, VIII, IX, XI, and XII were all within normal limits; factor VII was at the lower limits of normally or slightly decreased. Mr. Stuart's plasma failed to correct the defect of the patients plasma; however, a known factor VII deficient plasma was able to correct the abnormality. Factor X levels showed low (3–13%) only when assayed using tissue whole thromboplastin or tissue partial thromboplastin; the factor X assay using a Stypven‐cephalin mixture yielded normal or near normal values. The factor II + factor X level using a Stypven‐cephalin mixture appeared normal also. The significance of the findings is discussed. The results are tentatively interpreted as being due to an abnormal factor X rather than to a real deficiency.

Factor X Friuli Coagulation Disorder: Almost 50 Years Later

“…All homozygotes have to be considered as potential bleeders even though the severity of the bleeding manifestations is variable and usually moderate. [4][5][6][7] No brain hemorrhage or hemarthrosis have ever been seen in FX Friuli patients. This is in contrast with classical FX deficiency in which these bleeding manifestations, particularly the first one, are common.…”

“…4 In early 1970, we published in the Scand J Hematol, an article that was a restudy of the case previously published by Venturelli et al 14 We again concluded on the suspicion of the presence of an abnormal FX. 5 In 1968 to 1969, this patient was working in Milan and was seen by Prof De Cataldo of Milan City Hospital, who sent a sample of plasma to Prof Denson in Oxford. At that time, Prof Denson had developed suitable antibodies and had described abnormal FIX variants and abnormal FX forms.…”

“…All homozygotes have to be considered as potential bleeders even though the severity of the bleeding manifestations is variable and usually moderate. 4 –7…”

“…2,3 The FX Friuli variant was first suspected because of the presence, in some patients, of a normal Russell viper venom clotting time (RVVCT) together with prolonged partial thromboplastin and PTs. [4][5][6][7] The Complicated Story of the Discovery Friuli, a northeastern Italian region, was in the past a poor area. The Meduna River Valley, where FX Friuli was discovered, was particularly depressed economically.…”

A Comment About the Correct Attribution of the Discovery of FX Friuli Disorder

“…3 The defect had been originally recognized and described in Padua in 1970 and 1971 in a series of articles, which firmly established the clinical features and the peculiar laboratory pattern (low activity in the extrinsic and intrinsic systems, normal activity in the Russell viper venom assay, normal antigen) of the condition. [4][5][6] We cannot abstain from noting that it would have been scientifically correct to acknowledge this by quoting the original articles. Incidentally the patient presented by the authors belongs to the large kindred studied by us in 1970 and reported in one of the original articles (patient IVa of Figure1).…”