A rare cause of intracranial hemorrhage: factor X deficiency

Occurrence and management of severe bleeding episodes in patients with hereditary factor X deficiency

Vitamin K-dependent factor X (FX) plays an important role in thrombin formation, and a deficiency in FX can cause impaired coagulation, the severity of which is usually correlated with the degree of deficiency. Due to the critical role that FX plays in the coagulation cascade, FX deficiency is associated with a higher risk of bleeding than deficiencies in other coagulation factors. Patients with the hereditary autosomal-recessive homozygous form of FX deficiency, which occurs in approximately 1:1,000,000 individuals worldwide, are often diagnosed when they present with spontaneous life-threatening haemorrhage (most often intracranial haemorrhage) during the first month of life. In addition to central nervous system bleeds, other severe bleeding types experienced by such patients may include umbilical cord bleeding, gastrointestinal or pulmonary haemorrhage, intramuscular haematomas and/or haemarthrosis. Delayed treatment or inadequate replacement of FX may result in developmental delays, musculoskeletal disabilities or death. The high risk of recurrent severe bleeding necessitates prophylactic replacement therapy for many individuals with severe FX deficiency. Available products for replacement therapy include plasma-derived FX concentrate and prothrombin complex concentrates. Fresh-frozen plasma may be used when concentrates are not available but is a less efficient means of FX replacement. This article reviews the literature on severe bleeding in individuals with hereditary FX deficiency and discusses current treatment options.

In Utero Transfer of Adeno-Associated Viral Vectors Produces Long-Term Factor IX Levels in a Cynomolgus Macaque Model

The safe correction of an inherited bleeding disorder in utero prior to the onset of organ damage is highly desirable. Here, we report long-term transgene expression over more than 6 years without toxicity following a single intrauterine gene transfer (IUGT) at 0.9G using recombinant adeno-associated vector (AAV)-human factor IX (hFIX) in the non-human primate model we have previously described. Four of six treated animals monitored for around 74 months expressed hFIX at therapeutic levels (3.9%-120.0%). Long-term expression was 6-fold higher in males and with AAV8 compared to AAV5, mediated almost completely at this stage by random genome-wide hepatic proviral integrations, with no evidence of hotspots. Post-natal AAV challenge without immunosuppression was evaluated in two animals exhibiting chronic low transgene expression. The brief neutralizing immune reaction elicited had no adverse effect and, although expression was not improved at the dose administered, no clinical toxicity was observed. This long-term surveillance thus confirms the safety of late-gestation AAV-hFIX transfer and demonstrates that postnatal re-administration can be performed without immunosuppression, although it requires dose optimization for the desired expression. Nevertheless, eventual vector genotoxicity and the possibility of germline transmission will require lifelong monitoring and further evaluation of the reproductive function of treated animals.

Intracranial Hemorrhage as the First Manifestation of Severe Congenital Factor X Deficiency in a 20-Month-Old Male: Case Report and Review of the Literature

Factor X deficiency (FXD) is a rare bleeding disorder, which can result in severe bleeding symptoms such as intracranial hemorrhage (ICH). The most common bleeding symptoms are epistaxis and gum bleeding. ICH is reported in 9-26% of all patients with FXD, mostly during the first month of life. Here, we present a rare case of a male presenting with ICH at the age of 20 months as the first manifestation of FXD. Secondary prophylaxis with factor X substitution once weekly prevented further bleeding.

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.

Factor X deficiency presenting as a pseudotumor

The authors report their experience in successfully treating a 15-week-old child who became comatose following a spontaneous intracerebral hemorrhage. It was initially believed that a tumor in the right frontal lobe caused the hemorrhage. Coagulation studies revealed abnormal results on presentation, and the problem was only partially corrected after an infusion of fresh frozen plasma. The child underwent an emergency craniotomy in which the hematoma was evacuated, and a biopsy specimen was obtained from a firm mass at the base of the hematoma cavity. Postoperatively, the child recovered completely, and an analysis of detailed coagulation studies revealed that the child had a factor X deficiency. Histological analysis of the biopsy specimen revealed normal brain tissue with hemorrhagic infiltration. Subsequently, the child achieved normal developmental milestones. A diagnosis of congenital bleeding disorder should be considered in children with spontaneous intracerebral hemorrhage, even in those with no prior episode of extracerebral spontaneous hemorrhage.

Homozygous Factor X gene mutations Gly380Arg and Tyr163delAT are associated with perinatal intracranial hemorrhage

Intracranial hemorrhage (ICH) is a severe complication of Factor X (FX) deficiency. We report 6 homozygous patients with central nervous system (ICH) bleeds. Five patients are homozygous for the mutation Gly380Arg and one for the novel deletion Tyr163delAT. We describe the association of these mutations with ICH bleeding.

Severe congenital factor X deficiency with intracranial bleeding in two siblings

Congenital factor X deficiency is a rare autosomal recessive disorder that usually presents with variable bleeding tendency, prolonged prothrombin time and partial thromboplastin time. Therefore, it may be misdiagnosed as hemorrhagic disease of the newborn. Factor X level should be investigated for the definite diagnosis. We first report a new family whose two infants presented with severe intracranial bleeding at different times and were found to have congenital factor X deficiency. Plasma replacement therapy was not found to be efficacious in these infants. In conclusion, a possible factor X deficiency should be considered when a newborn presents with intracranial bleeding.