Molecular Diagnosis Of One Chinese Patient With Hemophilia B

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4790-4790
Author(s):  
Rong-Fu Zhou ◽  
Bo Gao ◽  
Jian Ou-yang
Keyword(s):  
De Novo ◽  
Conflicts Of Interest ◽  
Direct Sequencing ◽  
Coagulation Factor ◽  
Chinese Patient ◽  
Factor Ix ◽  
Hemophilia B ◽  
Coagulation Tests ◽  
Prolonged Aptt ◽  
Pcr Products

FTo investigate the molecular mutation leading to Hemophilia B in one patient. Methods FOne-stage method was used to detect APTT, PT, TT, Fibrinogen and FVIII:C, FIX:C. The genomic DNA was extracted from the peripheral blood of proband. All exons and their flanks of Factor IX gene were amplified by polymerase chain reaction (PCR). The PCR products were sequenced directly. Results FThe proband was a 20-month boy presenting with scalp hematoma after trauma. Regular coagulation tests showed that his APTT was 135.1s, PT 11.9s, TT 15.6s and Fibrinogen 2g/l. Normal mixed plasma could correct the prolonged APTT to 35s. His FIX:C was 6.4% and FVIII:C was normal. Direct sequencing of PCR products suggested that there was a 5085T>C mutation (NG_007994.1) in Exon1, and a 36060G>C mutation in Exon8 of F9 gene. The former mutation caused the substitution of Leu19 by Pro, which lies in -28th in signal peptide. The later mutation lead to the substituion of Gln370 by His. Conclusion FMutations of 5085T>C in Exon1 and 36060G>C in Exon8 might be the causes of coagulation factor IX defiency for the patient. These mutations are de novo ones according to the database presenting in http://www.factorix.org/. Disclosures: No relevant conflicts of interest to declare.

A Novel Case of Hemophilia B Due to a Partial Duplication of the Factor 9 Gene

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 4423-4423
Author(s):  
Ruth Wheeler ◽  
Jayanthi Alamelu ◽  
Jacqueline Cutler
Keyword(s):  
De Novo ◽  
Conflicts Of Interest ◽  
Direct Sequencing ◽  
Gene Copy Number ◽  
Factor Ix ◽  
Hemophilia B ◽  
Gene Copy ◽  
Coagulation Disorder ◽  
Severe Hemophilia ◽  
Bleeding Events

Abstract Abstract 4423 Hemophilia B is an X-linked recessive coagulation disorder. The disease is caused by a deficiency of procoagulant Factor IX and is characterised by easy bruising and prolonged bleeding and oozing after injury or surgery. The severity of the disease and the frequency of bleeding events vary, depending on the FIX clotting activity, and in severe cases males suffer from spontaneous joint and muscle bleeds which significantly impact on their health and quality of life. Hemophilia B is less common than Hemophilia A, with a frequency of approximately 1 in 25000 males worldwide. The F9 gene is located on the long arm of the × chromosome at Xq27. The gene comprises 8 exons, spanning approximately 33.5 kb DNA. The molecular basis of Hemophilia B is heterogeneous and to date over a 1000 different mutations have been reported, including missense and nonsense mutations, splicing mutations and large deletions. Here we report the identification of a previously uncharacterised duplication spanning a large part of the F9 gene in a patient with severe Hemophilia B. The patient, a 6 year old male of mixed Iranian and UK origin, was referred to the centre with severe Hemophilia B. He had a FIX level of less than 1iu/dL. No family history of bleeding diathesis could be confirmed due to loss of maternal family members in an earthquake. Mutation analysis of all exons including immediate flanking regions to allow detection of splice site mutations, and the 5’ and 3’ untranslated regions was performed by direct sequencing but no changes from the normal sequence were identified. There have been several reports of Hemophilia B being associated with partial duplications of the F9 gene so we analysed gene copy number using multiplex ligation-dependant probe amplification (MLPA). A large duplication, involving exons 2 to 6 was identified in the affected male. Subsequent analyses of maternal samples were normal, indicating that the mutation arose de novo. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Compound Heterozygous Nonsense Mutations Leading to Hereditary Deficiency of Coagulation Factor XI in a Chinese Pedigree

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 5032-5032
Author(s):  
Qian Li ◽  
Hui Zeng ◽  
Yong Xu ◽  
Min Zhou ◽  
Bing Chen ◽  
...  
Keyword(s):  
Conflicts Of Interest ◽  
Direct Sequencing ◽  
Gene Mutations ◽  
Coagulation Factor ◽  
Compound Heterozygous ◽  
Sequencing Analysis ◽  
Factor Xi ◽  
Nonsense Mutations ◽  
Prolonged Aptt ◽  
Dna Sequencing Analysis

Abstract The objective is to identify the gene mutations responsible for the deficiency of factor XI (FXI) in a Chinese pedigree. The FXI activity was tested with clotting assay. The F11 gene was amplified by PCR with direct sequencing. ClustalX-2.1-win and three online bioinformatics softwares were used to study the conservatism and harm of the mutation. The proband was a 70-year-old male and had a prolonged APTT of 67.8s. The corrected APTT was 28.3s and he had reduced FXI: activity of 0.8%. His son and daughter had normal APTT of 26s and 27.3s and FXI:C of 72% and 75%, respectively. DNA sequencing analysis showed the proband carried a compound heterozygous g.841C>T and g.1556G>A mutation , resulting in Ser281Stop and Trp519Stop, respectively, which caused premature termination of transcription in the F11. His son had the heterozygous g.841C>T mutation of F11 and his daughter had the heterozygous g.1556G>A mutation of F11. The three bioinformatics softwares indicated that the mutation had affected the function of the protein. The two nonsense mutations had been reported previously in different patient, but this is the first time to be reported in the proband, which was responsible for the decrease of FXI: activity. Disclosures No relevant conflicts of interest to declare.

scholarly journals Molecular analysis of hemophilia B in Poland: 12 novel mutations of the factor IX gene.

1999 ◽  
Vol 46 (3) ◽  
pp. 721-726 ◽  
Author(s):  
K Wulff ◽  
K Bykowska ◽  
S Lopaciuk ◽  
F H Herrmann
Keyword(s):  
Direct Sequencing ◽  
Point Mutations ◽  
Factor Ix ◽  
Hemophilia B ◽  
Heteroduplex Analysis ◽  
Missense Mutations ◽  
Nonsense Mutations ◽  
Pcr Products ◽  
Factor Ix Deficiency ◽  
High Degree

We examined the molecular basis of factor IX deficiency in 53 unrelated Polish patients with hemophilia B. Heteroduplex analysis and direct sequencing of polymerase chain reaction (PCR) products were applied to identify the gene defect. Forty-three different point mutations were detected in the factor IX gene of 47 patients. There were 29 missense mutations, 9 nonsense mutations, 4 splice site mutations and 1 point mutation in the promoter region. Twelve mutations were novel. The results of this study emphasize a very high degree of heterogeneity of hemophilia B.

scholarly journals Mutations causing hemophilia B in Algeria: Identification of two novel mutations of the factor 9 gene

2018 ◽  
Vol 19 (1) ◽  
pp. 52-58 ◽  
Author(s):  
ZIDANI ABLA ◽  
YAHIA MOULOUD ◽  
EL MAHMOUDI HEJER ◽  
GOUIDER EMNA ◽  
ABDI MERIEM ◽  
...  
Keyword(s):  
Direct Sequencing ◽  
Point Mutations ◽  
Coagulation Factor ◽  
Factor Ix ◽  
Hemophilia B ◽  
Causative Mutation ◽  
Novel Mutations ◽  
Mutation Database ◽  
Wide Range ◽  
The Family

Abla Z, Mouloud Y, Hejer El, Emna G, Abdi Meriem A, Ouarhlent Yamina O, Naouel S. 2018. Mutations causing hemophilia B in Algeria: Identification of two novel mutations of the factor 9 gene. Biodiversitas 19: 52-58. Hemophilia B (HB) (also known as Christmas disease; Christmas is the family name of the first patient.) is an X linked recessive hemorrhagic disorder caused by mutations in factor 9 (F9: is used for the gene) gene that leads to deficient or defective coagulation factor IX (FIX: is used for the protein). The variable phenotype of HB results from wide range of mutations affecting the F9 gene. Our study was aimed at molecular analysis of HB to identify the causative mutation in known patients with HB in a part of Algeria. For genotyping, polymerase chain reaction (PCR) and direct sequencing have been applied to all the essential regions of the F9 gene from 39 Algerian HB patients belonging to 13 unrelated families. We identified 10 different mutations. The identified mutations included 1 duplication and 9 substitutions. In total 9 point mutations were identified, of which 5 are located in exon 8, the hotspot region in the F9 gene. Among the 10 mutations, 2 are novel and not deposited in database sites nor described in recently published articles. The results of this study emphasize the heterogeneity of HB. In summary, our preliminary results will be used to build an Algerian mutation database which would facilitate genetic counseling.

scholarly journals Safety and Efficacy of New Nonacog Alfa Drug (Innonafactor) in Prophylactic Treatment in Patients with Severe and Moderate Hemophilia B

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3532-3532 ◽  
Author(s):  
Tatiana Andreeva ◽  
Vladimir Yu. Zorenko ◽  
Igor Davydkin ◽  
Valeria Konstantinova ◽  
Olga Zalepukhina ◽  
...  
Keyword(s):  
Adverse Events ◽  
Drug Administration ◽  
Prophylactic Treatment ◽  
De Novo ◽  
Conflicts Of Interest ◽  
Factor Ix ◽  
Hemophilia B ◽  
Low Grade ◽  
Prophylactic Therapy ◽  
K Value

Abstract During a controlled, randomized, open, prospective, multicenter clinical trial the efficacy and safety of a new domestically produced recombinant factor IX (FIX, nonacog alfa, CJSC "GENERIUM", Russia) were investigated in comparison with plasma drug Octanine® F (filtered) ("Octapharma pharmazeutika produktionsges mbH", Austria) for the prophylactic treatment of bleedings in patients with severe and moderate hemophilia B. After screening and a 4-day washout period 18 patients with moderate (n=8) and severe (n=10) hemophilia B were divided into 2 groups according to randomization: the 1st group patients (n=9) received the nonacog alfa, the 2nd group (n=9) Octanine F (fig. 1). In the 1st group there were 4 patients with severe hemophilia B (activity of FIX was less than 1%) and 5 patients with the moderate form of the disease (activity of FIX was 1-3%). In the 2nd group 6 patients had severe and 3 moderate hemophilia B (activity of FIX was 1-2,6%). In order to prevent bleeding nonacog alfa was injected slowly intravenously at a dose of 50±5 IU kg-1. Octanine F was infused at a dose of 30±5 IU kg-1. Drugs were injected 2-3 times per a week during 26±1 weeks (6 months). The main criterion of drug efficacy was the average number of bleedings within 6 months of prophylactic treatment. Anticipated average number of bleedings was determined based on the effectiveness of the original drug Benefix® (Pfizer, USA) and was 9±3 cases. Additional criteria of efficacy were severity of bleeding, activated partial thromboplastin time (APTT) and FIX activity before and 30 min after drug administration compared with normal values. In the 1st group 2 moderate bleeding episodes occurred in 2 patients, while in the 2nd group 10 hemorrhagic episodes occurred in 4 patients (1 episode was severe, 1 - moderate, and 8 were low grade). There were no significant differences in frequency of bleeding events. The average number of bleedings during the analyzed period in patients of the 1st group was 0,22±0,44. In patients of the 2nd group it was 1,11±1,97; the differences were statistically insignificant (p=0,24). In patients of both groups, the average number of bleeding was within planned range (fig. 2). Pharmacokinetics was evaluated by K-value (incremental recovery) and in vivo recovery (IVR). After carrying out of prophylactic therapy during 6 months, Incremental recovery of nonacog alfa was 1,24 ± 0,32 IU/DL per IU/kg. The Incremental recovery (K-value) of Octanine F was analogous and amounted to 1,14 ±0,29 IU/DL per IU/kg. During 6 months IVR of nonacog alfa was 47,56 ±13,56% and the IVR of Octanine F was not different and amounted to 49,05 ±15,68%. Prophylactic therapy was accompanied by normalization of coagulation activity of blood. On the 26th week of therapy APTT values taken 30 minutes after drug administration were 38,04 ±3,63 sec. in 1st group and 41,49 ± 3,44 sec. in the 2nd group. Safety assessment was performed in 18 patients. There were 6 adverse events in the 1st group and 12 in the 2nd group. All adverse events were not associated with drugs administration. Thus, the study shows that nonacog alfa (Innonafactor) is effective in prophylaxis of bleeding in patients with severe and moderate hemophilia B. The results are comparable with the results of the use of Octanine F. The study demonstrated that nonacog alfa (Innonafactor) with its pharmacodynamic and pharmacokinetic characteristics is comparable to Octanine F. Administration of nonacog alfa (Innonafactor)to patients with severe and moderate hemophilia B was accompanied by normalization of APTT and FIX activity and rising activity of FIX and its degree of recovery. Treatment with nonacog alfa (Innonafactor) was safe and without side effects, infection transmission, de novo inhibitor incident. Disclosures No relevant conflicts of interest to declare.

Aptamer Mediated Inhibition of Protein S

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 4946-4946
Author(s):  
William E. Plautz ◽  
Juliana Layzer ◽  
Bruce A. Sullenger ◽  
Rinku Majumder
Keyword(s):  
Conflicts Of Interest ◽  
Ex Vivo ◽  
Coagulation Factor ◽  
Protein S ◽  
Factor Ix ◽  
Hemophilia B ◽  
Factor X ◽  
Initial State ◽  
Gla Domain

Abstract Protein S (PS) is an anticoagulant that acts as a direct allosteric inhibitor of the activated form of factor IX (FIXa); FIXa is a coagulant, in both the presence and absence of its cofactor, factor VIIIa. Inhibition of FIXa by PS results in a retarded rate of activation of factor X; FX plays an important role as the initial protease common to the two pathways of blood coagulation. Factor IX (FIX) deficiencies present in the form of varying severities of hemophilia B; additionally, elevated levels of PS result in lengthened clotting times. We intend to increase the efficacy and functional lifetime of natural and infused FIXa in hemophilia B patients by creating a high affinity aptamer that selectively inhibits PS in its interaction with FIXa. Although inhibitory aptamers that target pro-coagulant proteins have been produced in a facile manner, the hemostasis field has yet to direct its sights towards a therapeutically viable aptamer that inhibits a naturally occurring anticoagulant. Through the use of previously selected, and experimentally successful, aptamer pools targeting either Gla-domain or plasma proteomes, we were able to use SELEX to select novel PS ligands. After two rounds of aptamer selection, using the focused pools as an initial state, we have found by nitrocellulose binding assays a strong enrichment from the focused Gla domain proteome, whereas the plasma proteome showed a weaker response. Following development of an inhibitory PS aptamer, we will perform fluorescence binding and substrate cleavage studies to obtain kinetic constants, and ex vivo studies, including aPTT and thrombin generation assays, to demonstrate aptamer efficacy in a physiological system. Ultimately, we plan to test the aptamer in vivo, to demonstrate its use as a possible adjunct therapy to current treatments of hemophilia B. Disclosures No relevant conflicts of interest to declare.

scholarly journals Diagnosis and Treatment of Acquired Hemophilia: One Single-Center Experience from PR. China

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 4250-4250
Author(s):  
Rong-Fu Zhou ◽  
Yueyi Xu ◽  
Wenjin Gao
Keyword(s):  
Hemophilia A ◽  
Conflicts Of Interest ◽  
Clinical Manifestations ◽  
Coagulation Factor ◽  
Factor Vii ◽  
Acquired Hemophilia A ◽  
Acquired Hemophilia ◽  
Coagulation Factor Vii ◽  
Prolonged Aptt ◽  
Inhibitor Titer

Abstract Objective: To deepen the understanding of the clinical manifestations of acquired hemophilia A for timely and correctly treatment. Methods: The clinical data of the acquired hemophilia A patients diagnosed in the hospital from Jan 2006 to Mar 2021 were retrospectively analyzed, and the relevant literature was reviewed. Results: 17 patients with acquired hemophilia A, male: female =10: 7, median age 61 years (19 to 78 years), were diagnosed and treated in the hospital with the median time from the onset to diagnosis 21 days (2 days to 6 months). Six patients had comorbidity, including hepatitis B carrying, chronic myelomonocytic leukemia, diabetes, hypertension and positive autoantibodies, pemphigoid and gastric cancer, respectively. Other 11 patients were healthy before the onset. All patients had large large ecchymosis of skin, and one case was combined with hematuria, and one case with retroperitoneal hematoma. All patients had APTT extension (45s-144.7s) and the prolonged APTT could not be corrected with normal mixed plasma with and without incubation at 37℃ for 2 hours. FVIII activity was 1% - 8.9% and inhibitor titer 2 - 128 Bu/ml. All patients with bleeding were with prothrombin complex/recombinant activated coagulation factor VII, some of them with pd-coagulation factor FVIII preparations. Inhibitors were removed with prednisone acetate (1 case) + chemotherapy (1 case), prednisone acetate / + CTX (11 cases) + chemotherapy (1 case), prednisone acetate/prednisolone + mabthera (2 cases) + CTX (1 case), respectively. The removal time of inhibitor was from 8 days to 4 years. During the treatment process, two patients developed lower extremity venous thrombosis, and one patient was complicated with lung infection. Conclusion: Patients with unexplained bleeding and prolonged APTT should be conducted normal mixed plasma correction test, coagulation factor activity and inhibitor titer examination. After correctly diagnosis, bypass agents /coagulation factor VIII preparations should be given timely for hemostasis, protocol based on glucocorticoid + CTX/mabthera to remove the inhibitor and symptomatic treatment for patients with primary comorbidity disease at the same time. Disclosures No relevant conflicts of interest to declare.

scholarly journals Mutation Spectrum and Genotype–Phenotype Analyses in a Pakistani Cohort With Hemophilia B

2017 ◽  
Vol 24 (5) ◽  
pp. 741-748 ◽  
Author(s):  
Muhammad Tariq Masood Khan ◽  
Arshi Naz ◽  
Jawad Ahmed ◽  
Tahir Shamsi ◽  
Shariq Ahmed ◽  
...  
Keyword(s):  
Clinical Phenotype ◽  
Direct Sequencing ◽  
In Silico Analysis ◽  
Genetic Alterations ◽  
Factor Ix ◽  
Hemophilia B ◽  
Mutation Spectrum ◽  
Coagulation Activity ◽  
Exon 2 ◽  
Novel Variants

This study aimed to (1) identify F9 genetic alterations in patients with hemophilia B (HB) of Pakistani origin and (2) determine the genotype–phenotype relationships in these patients. Diagnosed cases of HB were identified through registries at designated tertiary health-care centers across the country. Consenting patients were enrolled into the study. The factor IX (FIX) coagulation activity (FIX:C) and key clinical features were recorded. Direct sequencing of F9 was carried out in all patients. All the variants identified were analyzed for functional consequences employing in silico analysis tools. Accession numbers from National Center of Biotechnology Information ClinVar database were retrieved for the novel variants. Genotype–FIX:C relationships were determined followed by FIX:C clinical phenotype assessment. A total of 52 patients with HB from 36 unrelated families were identified, which mainly comprised patients with moderate HB (n = 35; 67.3%). Among these, 35 patients from 22 unrelated families could be contacted and enrolled into the study. Missense variants were the most frequent (58.8%), followed by nonsense variants (17.6%). A missense, a short insertion, and a nonsense novel variants in exon 2, 6, and 7, respectively, were also identified. The disease manifested FIX:C heterogeneity in relation to the corresponding mutation in a significant number of cases. Clinical phenotype heterogeneity was also observed in relation to FIX:C-based severity assessment. We concluded that the registered FIX-deficient population of Pakistan mainly comprises moderate HB. F9 mutation spectrum in Pakistani patients with HB is heterogeneous. The HB population of Pakistan manifests a significant amount of genotype–FIX:C and FIX:C–clinical phenotype heterogeneities.

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