Classical Factor X Deficiency

Abstract

A case of classical factor X deficiency is reported. The propositus is a 28-year-old male who presented easy bruising, epistaxis, hematomas, hematuria and occasional hemartrosis since early childhood. The severely prolonged prothrombin time was corrected by normal serum but not by adsorbed normal plasma. The abnormality was not corrected by the plasma of a patient with factor X deficiency, but by the plasma of patients with factor II or VII deficiencies. Partial thromboplastin time, prothrombin consumption and the thromboplastin generation test were abnormal. The thromboelastogram showed a prolonged ‘K’ and ‘r’ together with a normal ‘ma’. Factor X was very low (<1%). Platelet tests were normal. No factor X band or precipitates were seen on electroimmunoassay and on the cross-over electrophoresis. The non-consanguineous parents and several other members of the family were found 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)

“…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).…”

“…The mutations found were Pro343Ser for FX Friuli and Arg251Trp for FX Padua and Cys350Phe, Gly380Arg, and delC556 (Table 1). For the heterozygotes of two families with FX true deficiency, genetic analysis could not be performed (6,14).…”

“…Bleeding manifestations in heterozygote patients for autosomal recessive conditions such as FII, FV, FVII, and FX deficiency have not been satisfactorily defined yet. As far as heterozygotes for FX deficiency are concerned, the few data available indicate that they may present a mild bleeding tendency (5)(6)(7). However, no definitive study is available.…”

Platelet Aggregation and Adhesiveness in Classical Factor X Deficiency and in the Abnormal Factor X (Factor X Friuli) Coagulation Disorder

“…Factor X deficient plasma was obtained from a patient pre viously reported [8]. Abnormal factor X (factor X Friuli) plasma was obtained from a patient previously reported [5].…”

“…We had the unusual opportunity during the past years to study a patient with severe factor X deficiency and several patients with the fac tor X Friuli abnormality [4,5,7,8]. This is the first paper dealing with platelet aggregation in factor X deficient or abnormal factor X plasmas.…”