The clinical findings and prophylactic treatment in children with factor X deficiency.

Factor X (FX) is the component of both extrinsic and intrinsic coagulation cascade and is the first enzyme of the common pathway which results in thrombus. Congenital FX deficiency (FXD) is an extremely rare coagulation defect. In this study, we aimed to investigate the clinical and laboratory data of the patients diagnosed with FXD. The files of the 15 patients (7 female, 8 male) diagnosed and followed up for FXD within the last 4 years were evaluated retrospectively. The mean age of the patients was 29 months (min-max:1-144 months). The most presenting complaints were easy bruisability (n = 8; 53%) and epistaxis (n = 8; 53%). FX levels were <1% in six patients, 1-5% in four patients, and >5% in five patients. Heparin added-Protrombin Complex was used for prophlaxy (n = 11; 73%). Any treatment-related complication was not observed. Heparin-added PCC can be used safely for effective prophlaxy. We suggest that family history is important when considering prophlaxy and in patients with life-threatening bleeding or with FXD sibling the prophlaxy should be introduced in the early course.

Severe factor X deficiency due to a homozygous mutation (Cys364Arg) that disrupts a disulphide bond in the catalytic domain.

Severe factor X deficiency (<0.01 IU mL(-1)) is a rare disorder producing a major bleeding tendency including umbilical cord, joint and intracranial haemorrhage. We present the first case of a child homozygous for a g.1177T > C missense alteration, predicted to disrupt the catalytic domain, and resulting in severe FX deficiency. The child suffered intracranial haemorrhage and now receives regular prophylaxis with a prothrombin complex concentrate. Our experience and a review of the literature suggest that optimal frequency of dosing is likely to be two or three times weekly and that the risk of thrombosis is very small.

The role of primary prophylactic factor replacement therapy in children with severe factor X deficiency.

Severe factor X (FX) deficiency is one of the severest inherited coagulation disorders. Clinical manifestations include umbilical cord, mucosal, joint and central nervous system bleeding. Four Irish children with severe FX deficiency presented with umbilical cord bleeding. One developed an intraperitoneal haemorrhage and another an intracranial bleed. Prophylaxis, using intermediate purity Factor IX concentrate, was commenced within the first month of life, necessitating the insertion of central venous access devices in two of the children. All children have normal joint function, suggesting that prophylaxis commenced early in life reduces the incidence of arthropathy and improves quality of life.

Prophylactic treatment of severe factor X deficiency with prothrombin complex concentrate.

Factor X (FX) deficiency is an autosomal recessive trait that occurs in fewer than 1 in 500 000 people. Not surprisingly, reports of prophylactic treatment for FX deficiency are exceedingly rare. We now report our experience of the use of prophylactic therapy in a FX-deficient patient. This 18-year-old African-American male presented at the age of 4(1/2) years with an FX level < 1%. Treatment was on demand with prothrombin complex concentrates (PCCs) given at two times the dose per kilogram of body weight for factor IX. He experienced frequent epistaxis, soft tissue bleeding and joint bleeding. The development of a target joint (right ankle) prompted the initiation of prophylactic treatment in the beginning of 1998 to the present with 30 units kg(-1) Profilnine twice per week via a home infusion programme. If breakthrough bleeding occurred, he was instructed to infuse another dose. He was instructed that Profilnine should not be infused in more than two doses in 24 h or on more than three consecutive days. A trough level drawn 48 h post-infusion showed an FX level of 30%. In the initial 12 months with prophylactic treatment, there was no breakthrough bleeding. Subsequently, with an additional 11 months of follow-up, he has reported one bleed. He rates his quality of life improved since starting prophylactic treatment. There have been no thrombotic events. Prophylaxis with PCC for FX deficiency with adequate education and follow-up can be performed capably in the home setting with a resultant decrease in the frequency of bleeding and attendant complications.