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Congenital factor (F) VII deficiency is a bleeding disorder caused by a heterogeneous pattern of mutations in the F7 gene. Protein misfolding due to mutations is a strong candidate mechanism to produce the highly represented type I FVII deficiency forms, characterized by a concomitant deficiency of FVII antigen and activity. Misfolded proteins can accumulate within the endoplasmic reticulum (ER) causing ER stress with subsequent activation of the unfolded protein response (UPR). So far, there are limited data on this important issue in FVII deficiency. In this study, we chose as candidate FVII model mutations, the p.Q160R, p.I289del and p.A354V-p.P464Hfs, which are all associated with severe to moderate type I FVII deficiency. In vitro expression of the recombinant (r) mutants rFVII-160R, rFVII-289del or rFVII-354V-464Hfs, which are characterized by either amino acid substitution, deletion, or by an extended carboxyl terminus, demonstrated inefficient secretion of the mutant proteins, probably caused by intracellular retention and association with ER chaperones. Both ER stress and UPR were activated following expression of all FVII mutants, with the highest response for rFVII-289del and rFVII-354V-464Hfs. These data unravel new knowledge on pathogenic mechanisms leading to FVII deficiency, and support the investigation of pharmaceutical modulators of ER stress and UPR as therapeutic agents.

SummaryIn sepsis, binding of factor VII (FVII:C) and activated factor VII (FVIIa) with tissue factor is the key step of coagulation resulting in disseminated intravascular coagulation (DIC). We conducted a prospective cohort study among 47 septic patients, aged 8 months to 18.8 years. They were initially divided into three groups of no DIC (n=27), non-overt DIC (n=14) and overt DIC (n=6). Blood samples were collected at 0, 24 and 48 hours (h) after the onset of sepsis. At the onset of sepsis, FVII:C tended to be lower in the non-overt DIC [median 57% (interquartile range [IQR] 41–80)] and overt DIC groups [33% (23–52)] than that in the no DIC group [65% (44–87)]. Whereas FVIIa tended to be lower in the overt DIC group [1.29% (0.50–4.19)] than those in the non-overt DIC [3.01% (1.01–5.24)] and no DIC groups [2.49% (1.14–3.13)]. At 24 h, FVII:C was significantly lower in the non-overt DIC [57% (41–101)] and overt DIC groups [31% (28–49)] than that in the no DIC group [83% (70–102)]. While FVIIa was significantly lower in the overt DIC group [2.15% (0.86–3.96)] than that in the no DIC group [3.83% (2.90–5.46)]. Using FVII:C

SummaryPatients with the haemophilia B Leyden phenotype show a distinct pattern of factor IX expression characterized by a post-pubertal increase in FIX levels and the remission of clinical symptoms in adult life. This phenotype has previously been linked to single base mutations within transcription factor binding sites in a region of ∼40 bp around the major start point of transcription of the FIX gene. Here we report a novel mutation in this region within the transcription factor C/EBP binding site at +1 to +18. The mutation is a single base pair deletion from a triplet of thymine residues at +6 to +8. We show that the extent to which this mutation disrupts the binding of C/EBP to its binding site is less marked than the disruption caused by the +13 A→G mutation of FIX Norwich (1). This correlates with age-matched phenotypic data we have available for the patient reported here and that of FIX Norwich.

SummaryThe molecular basis of haemophilia B is heterogeneous and many mutations of the Factor IX (FIX) gene have been characterised. Using the allele-specific arrayed primer extension (ASAPEX) technology, we have designed a FIX array to simultaneously analyse 69 mutations found in British, Thai and Chinese patients. This technology overcomes the problem of multiple reverse dot-blot analysis and has a 100% accuracy in the detection of both affected subjects and carriers in families with known mutations. In seven unknown mutations from Thailand, the array could detect the specific mutation in five and in the remainders the normal primer at specific spots failed to extend due to a mutation a few nucleotides upstream, thus allowing their identification. Hence this FIX array can detect 53% of the 2891 mutation entries in the FIX database. Each of the microarray slide can be used for three different test samples and would be useful for carrier testing for common mutations and prenatal diagnosis. It is simpler and more cost effective than genome sequencing and would be particularly useful in laboratories with limited technical capabilities.

Experiences with Recombinant Factor VIIa for the Prevention of Bleeding in Patients with Chronic Liver Disease Undergoing Percutaneous Liver Biopsies and Endoscopic Retrograde Cholangiopancreatography (ERCP)

Patients with the haemophilia B Leyden phenotype show a distinct pattern of factor IX expression characterized by a post-pubertal increase in FIX levels and the remission of clinical symptoms in adult life. This phenotype has previously been linked to single base mutations within transcription factor binding sites in a region of approximately 40 bp around the major start point of transcription of the FIX gene. Here we report a novel mutation in this region within the transcription factor C/EBP binding site at +1 to +18. The mutation is a single base pair deletion from a triplet of thymine residues at +6 to +8. We show that the extent to which this mutation disrupts the binding of C/EBP to its binding site is less marked than the disruption caused by the +13 A--G mutation of FIX Norwich (1). This correlates with age-matched phenotypic data we have available for the patient reported here and that of FIX Norwich.

Combined Fresh Frozen Plasma with Recombinant Factor VIIa in Restoring Hemostasis for Invasive Procedures in Children with Liver Diseases

Successful Epistaxis Control in a Patient with Glanzmann Thrombasthenia by Increased Bolus Injection Dose of Recombinant Factor VIIa

Inversion of Intron 22 of the Factor VIII Gene in a Girl with Severe Hemophilia A and Turner’s Syndrome