Genetic Basis and Carrier Detection of Hemophilia B of Chinese Origin

1993 ◽  
Vol 69 (03) ◽  
pp. 247-252 ◽  
Author(s):  
Shu-Wha Lin ◽  
Ming-Ching Shen
Keyword(s):  
Amino Acid ◽  
Gene Deletion ◽  
Direct Sequencing ◽  
Screening Method ◽  
Point Mutations ◽  
Factor Ix ◽  
Hemophilia B ◽  
Sscp Analysis ◽  
Amino Acid Residues ◽  
Chinese Origin

SummaryWe have characterized the genetic defects of 17 hemophilia B patients of Chinese origin by means of the polymerase chain reaction (PCR) and direct sequencing. The single-strand conformation polymorphism (SSCP) was used as an initial screening method to analyze the entire coding region and the flanking introns of each individual’s factor IX gene. The abnormal exons were subsequently amplified and the nucleotide sequence determined. Of the 17 patients studied, 16 had single point mutations and one had a gross gene deletion of exons VII and VIII of factor IX. Among these 16 factor IX variants with point mutations 13 were missense and two were nonsense mutations. The remaining one had a nucleotide deleted, resulting in frame shifting at amino acid residue 97. A total of ten novel mutations, including the one with gross gene deletion, are reported in this study which have not been described previously. Five of the remaining seven variants were missense mutations with novel amino acids substituted for residues 127, 132, 180, 207, and 215, respectively. Mutations containing different amino acid residues at those positions have been reported. The last two are variants that have already been described to contain mutations at amino acid residues 333 and 365, respectively. To evaluate the efficiency of SSCP analysis in assessing the mutated exons and to further confirm our results we sequenced the entire exons of all 17 factor IX genes. The mutations detected by SSCP method were indeed the only mutation identified in each factor IX variant. The SSCP analysis and direct sequencing have also allowed us to circumvent the difficulties of carrier determination for Chinese by direct detection of the abnormal factor IX alleles inherited by the females.

Characterization of Genetic Defects of Hemophilia B of Chinese Origin

1991 ◽  
Vol 66 (04) ◽  
pp. 459-463 ◽  
Author(s):  
Shu-Wha Lin ◽  
Ming-Ching Shen
Keyword(s):  
Amino Acid ◽  
Novel Mutation ◽  
Translation Termination ◽  
Direct Sequencing ◽  
Factor Ix ◽  
Hemophilia B ◽  
Genetic Defects ◽  
Antigen Level ◽  
Chinese Origin ◽  
Nucleotide Residue

SummaryTo define the precise genetic defects of hemophilia B of Chinese origin, we have used the polymerase chain reaction (PCR) combined with direct sequencing to analyze the amplified DNA fragments containing the entire coding regions and their flanking introns of the factor IX gene from 6 affected individuals. Among these patients, two are siblings with normal factor IX antigen level (CRM+) yet reduced factor IX clotting activity (28%). Analysis of their factor IX genes revealed a G to A transition at nucleotide residue 10394, which causes substitution of an arginine for a glycine at amino acid residue 48. This is a novel mutation which resides in the first EGF-like domain of factor IX. Studies of two other hemophilia B patients with CRMr phenotypes (factor IX antigen level <35%, and clotting activity <1%), demonstrated a distinct mutation in each individual's factor IX gene. In one case, a guanine to adenine (residue 6365) transition results in replacement of arginine by glutamine at the –4 codon of the propeptide of factor IX. In the other, thymine at 6442 was mutated to cytosine which causes an arginine for cysteine substitution at residue 23. We have also characterized 2 discrete CRM- patients. Both exhibited an identical mutation at nucleotide residue 6460 which generates a translation termination codon (CGA to TGA) at the 29th amino acid. The mutation created a new NlaIII restriction enzyme site which could be used to identify this variant.

Six Novel and Three Recurrent Mutations in Nine Austrian Patients with Hemophilia B

1994 ◽  
Vol 72 (01) ◽  
pp. 074-077 ◽  
Author(s):  
J Walter ◽  
I Pabinger-Fasching ◽  
H H Watzke
Keyword(s):  
Direct Sequencing ◽  
Point Mutations ◽  
Factor Ix ◽  
Hemophilia B ◽  
Causative Mutation ◽  
Genetic Defects ◽  
Missense Mutations ◽  
Enzymatic Amplification ◽  
Recurrent Mutations ◽  
Polymerase Chain

SummaryIn this report we describe the molecular basis of the factor IX (FIX) deficiency in nine patients with severe (n = 6), moderate (n = 1) or mild (n = 2) hemophilia B. The following genetic defects were identified by enzymatic amplification with the polymerase chain reaction (PCR) and subsequent direct sequencing of all exons and exon-intron-junctions: patient B.B. (FIX “Vienna I”): deletion of nucleotides 6343 to 6362; patient M.H. and W. J. (FIX “Vienna II”): nucleotide 17704 (C to G), Gin 97 to Glu; patient L. K. (FIX “Vienna III”): nucleotide 17761 (C to T), Arg 116 to stop; patient U. A. (FIX “Vienna IV”): nucleotide 10415 (C to G), Pro 55 to Ala; patient H.G. (FIX “Vienna V”): nucleotide 6488 (C to T), Thr 38 to lie; patient H. M. (FIX “Vienna VI”): nucleotide 31276 (G to C), Trp 385 to Cys; patient L. C. (FIX “Vienna VII”): deletion of nucleotide 6700; patient S.F. (FIX “Vienna VIII”): nucleotide 10392 (A to T), Asp 47 to Val. The causative mutation was detected in the FIX gene in each of the nine patients with hemophilia B. There was one small deletion, one point deletion and seven point mutations. The latter include six missense mutations and one nonsense mutation. The mutations in Vienna III, IV and V have already been described in previous studies. The two deletions, Vienna I and Vienna VII have not been reported previously. The genetic defects observed in Vienna II, VI and VIII are novel missense mutations which result in amino acid changes at residues 97,47 and 385, respectively.

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.

Point Mutations in Four Hemophilia B Patients from China

1990 ◽  
Vol 64 (02) ◽  
pp. 302-306 ◽  
Author(s):  
N S Wang ◽  
S H Chen ◽  
A R Thompson
Keyword(s):  
Dna Sequences ◽  
Genomic Dna ◽  
Stop Codon ◽  
Direct Sequencing ◽  
Point Mutations ◽  
Factor Ix ◽  
Hemophilia B ◽  
Chinese Patients ◽  
Severe Hemophilia ◽  
Plasma Factor

SummaryPoint mutations in factor IX genes of four unrelated Chinese patients with hemophilia B have been identified by direct sequencing of amplified genomic DNA fragments. These four mutations occur in exon 8 of the factor IX gene. A C to T transition at nucleotide 30,863 changes codon 248 from Arg (CGA) to a new Stop codon (TGA), described in a previous family as factor IXMalmo3 (Green P M et al., EMBO J 1989; 8: 1067). A G to A transition, at nucleotide 31,051 changes codon 310 from Trp (TGG) to a nonsense or Stop codon (TGA; factor IXchongqing2)- A G to A transition at nucleotide 31,119 changes codon 333 which is for Arg (CGA) in normal factor IX, to one for Gin (CAA) in the variant previously described as factor IXLondon2 (Tsang T C et al., EMBO J 1988; 7: 3009) in a patient with moderately severe hemophilia B. The fourth patient has a novel C to A transversion at nucleotide 31,290, which corresponds to replacement of codon 390 which is for Ala (GCA) in normal factor IX, to one for Glu (GAA) in a patient with moderately severe hemophilia B (factor IXChongqing3)- DNA sequences of amplified fragments from mothers of three showed both their son’s variant and a normal nucleotide at the appropriate position, indicating that they are carriers. The fourth patient’s (factor IXMalmo3) mother, whose DNA was not evaluable, was most probably a carrier because of her low plasma factor IX levels.

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 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.

scholarly journals Activation of Ha-ras p21 by substitution, deletion, and insertion mutations.

1985 ◽  
Vol 5 (8) ◽  
pp. 1809-1813 ◽  
Author(s):  
R G Chipperfield ◽  
S S Jones ◽  
K M Lo ◽  
R A Weinberg
Keyword(s):  
Amino Acid ◽  
Point Mutations ◽  
Normal Function ◽  
Site Directed Mutagenesis ◽  
Directed Mutagenesis ◽  
Amino Acid Residues ◽  
Transforming Activity ◽  
Ras P21 ◽  
Ras Oncogenes ◽  
Insertion Mutations

The transforming activity of naturally arising ras oncogenes results from point mutations that affect residue 12 or 61 of the encoded 21-kilodalton protein (p21). By use of site-directed mutagenesis, we showed that deletions and insertions of amino acid residues in the region of residue 12 are also effective in conferring oncogenic activity on p21. Common to these various alterations is the disruption that they create in this domain of the protein, which we propose results in the inactivation of a normal function of the protein.

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.

scholarly journals Mefloquine and New Related Compounds Target the F0 Complex of the F0F1 H+-ATPase of Streptococcus pneumoniae

2002 ◽  
Vol 46 (6) ◽  
pp. 1680-1687 ◽  
Author(s):  
Antonio Javier Martín-Galiano ◽  
Begoña Gorgojo ◽  
Calvin M. Kunin ◽  
Adela G. de la Campa
Keyword(s):  
Streptococcus Pneumoniae ◽  
Amino Acid ◽  
Proton Translocation ◽  
Point Mutations ◽  
Amino Acid Residues ◽  
Transmembrane Helices ◽  
Inhibition Of Growth ◽  
Pneumococcal Strain ◽  
Resistant Strains ◽  
Related Compounds

ABSTRACT The activities of mefloquine (MFL) and related compounds against previously characterized Streptococcus pneumoniae strains carrying defined amino acid substitutions in the c subunit of the F0F1 H+-ATPase were studied. In addition, a series of MFL-resistant (Mflr) strains were isolated and characterized. A good correlation was observed between inhibition of growth and inhibition of the membrane-associated F0F1 H+-ATPase activity. MFL was about 10-fold more active than optochin and about 200-fold more active than quinine in inhibiting both the growth and the ATPase activities of laboratory pneumococcal strain R6. Mutant strains were inhibited by the different compounds to different degrees, depending on their specific mutations in the c subunit. The resistant strains studied had point mutations that changed amino acid residues in either the c subunit or the a subunit of the F0 complex. Changes in the c subunit were located in one of the two transmembrane α helices: residues M13, G14, G20, M23, and N24 of helix 1 and residues M44, G47, V48, A49, and V57 of helix 2. Changes in the a subunit were also found in either of the transmembrane α helices, helix 5 or 6: residue L186 of helix 5 and residues W206, F209, and S214 of helix 6. These results suggest that the transmembrane helices of the c and a subunits interact and that the mutated residues are important for the structure of the F0 complex and proton translocation.

scholarly journals The Impacts of G4S Mutation on N-glycosylation and conformation of the Human Coagulation Factor IX GLA domain: In silico and In vitro Analysis

2021 ◽  
Author(s):  
Fahimeh Ghasemi ◽  
Mina Maddah ◽  
Hourieh Kalhor ◽  
Mohsen Khorashadizadeh ◽  
Alireza Zomorodipour
Keyword(s):  
Amino Acid ◽  
Coagulation Factor ◽  
Glycosylation Site ◽  
Factor Ix ◽  
Hemophilia B ◽  
Phospholipid Bilayer ◽  
Single Amino Acid ◽  
Missense Mutations ◽  
Coagulation Factor Ix ◽  
Gla Domain

Abstract Missense mutations are the most prevalent form of mutation in hemophilia B patients. These alterations may result in the creation of novel and non-native N-glycosylation sites (Asn-X-Ser/Thr) through single amino acid substitutions. The pathogenic mechanisms of N-glycosylation mutations in hemophilia B patients have not been extensively studied yet. By survey among known missense mutations, we found only one N-glycosylation mutation in the γ-carboxyglutamic-rich (GLA) domain of the human coagulation factor IX (hFIX). This mutation that was reported in patients with mild and moderate hemophilia B, is caused by G4S amino acid substitution. To investigate the possibility of glycan attachment to the novel N-glycosylation site in G4S-mutant hFIX and the occurrence of hyperglycosylation, site-directed mutagenesis was applied to introduce the selected mutation into the coding sequence of the hFIX. The nucleotide sequences of the both native and G4S-mutant hFIX were separately cloned into the pcDNA3.1 expression plasmid and transiently expressed in HEK293T cells. Our results from gradient SDS-PAGE and western blotting analysis of the both recombinant native and mutant hFIX demonstrated no glycan attachment to the new N-glycosylation site in the G4S-mutant hFIX. Molecular dynamics (MD) simulation was also conducted to provide atomistic insights into structure and behavior of the native and G4S-mutant GLA domains in the both free and membrane-bound states. The results revealed that the mutation slightly affected the dynamic behavior of the mutant GLA domain. The conformational analysis proved that the native GLA domain had less fluctuation and more stability than the mutant GLA domain. The slight conformational changes may influence the binding capacity and interaction of the mutant GLA domain to phospholipid bilayer which is necessary for coagulation activity of the hFIX. These findings were in accordance with the nature of the G4S mutation which causes mild hemophilia B.

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