Double Strand Conformation Polymorphism (DSCP) Detects Two Point Mutations at Codon 280 (AAC→ATC) and at Codon 431 (TAC→AAC) of the Blood Coagulation Factor VIII Gene

1993 ◽  
Vol 69 (05) ◽  
pp. 473-475 ◽  
Author(s):  
W C Pieneman ◽  
P H Reitsma ◽  
E Briët

SummaryHemophilia A is a hereditary, X-linked, bleeding disorder that is caused by a defect in the factor VIII gene. Here, we report two novel point mutations in the factor VIII gene that result in an aberrant electrophoretic mobility of double strand PCR fragments (double strand conformation polymorphism, DSCP). In exon 9 a TAC→AAC mutation at codon 431, replacing Tyr by Asn, was observed in a family (A211) with moderately severe hemophilia A. A family with mild hemophilia A revealed an A→T mutation in codon 280 (exon 7) that results in the replacement of Asn by Ile. One of these two mutations was not detected in an analysis based on single strand conformation polymorphisms (SSCP).At present we have no explanation for the effect of the nucleotide changes on the electrophoretic mobility of double strand DNA. Although DSCP is not able to detect all mutations the combination of DSCP analysis with SSCP analysis increases the sensitivity in a screening for factor VIII mutations.

1999 ◽  
Vol 82 (08) ◽  
pp. 555-561 ◽  
Author(s):  
Douglas Jolly ◽  
Judith Greengard

IntroductionHemophilia A results from the plasma deficiency of factor VIII, a gene carried on the X chromosome. Bleeding results from a lack of coagulation factor VIII, a large and complex protein that circulates in complex with its carrier, von Willebrand factor (vWF).1 Severe hemophilia A (<1% of normal circulating levels) is associated with a high degree of mortality, due to spontaneous and trauma-induced, life-threatening and crippling bleeding episodes.2 Current treatment in the United States consists of infusion of plasma-derived or recombinant factor VIII in response to bleeding episodes.3 Such treatment fails to prevent cumulative joint damage, a major cause of hemophilia-associated morbidity.4 Availability of prophylactic treatment, which would reduce the number and severity of bleeding episodes and, consequently, would limit such joint damage, is limited by cost and the problems associated with repeated venous access. Other problems are associated with frequent replacement treatment, including the dangers of transmission of blood-borne infections derived from plasma used as a source of factor VIII or tissue culture or formulation components. These dangers are reduced, but not eliminated, by current manufacturing techniques. Furthermore, approximately 1 in 5 patients with severe hemophilia treated with recombinant or plasma-derived factor VIII develop inhibitory humoral immune responses. In some cases, new inhibitors have developed, apparently in response to unnatural modifications introduced during manufacture or purification.5 Gene therapy could circumvent most of these difficulties. In theory, a single injection of a vector encoding the factor VIII gene could provide constant plasma levels of factor in the long term. However, long-term expression after gene transfer of a systemically expressed protein in higher mammals has seldom been described. In some cases, a vector that appeared promising in a rodent model has not worked well in larger animals, for example, due to a massive immune response not seen in the rodent.6 An excellent review of early efforts at factor VIII gene therapy appeared in an earlier volume of this series.7 A summary of results from various in vivo experiments is shown in Table 1. This chapter will focus on results pertaining to studies using vectors based on murine retroviruses, including our own work.


Author(s):  
Maysoon Mohammed Hassan

The background:One of the prevalent main concerns in the medical world is the identification of Intron22 mutations in the Factor VIII gene carried by Iraqi patient in Wasit town, in Iraq suffering Hemophilia A (classical hemophilia) which is related to a X-chromosome recessive haemorrhage afflictions as the result of a flaw in the coagulation factor VIII (FVIII). It is essentially related with F8 mutations of Intron22 in version which forms the most typical kind of mutations of blood afflictions worldwide involving half the patients suffering from severe Hemophilia A that possesses mutations, in addition to Intron 1 inversion suffered by 5% of severe Hemophilia A patients.All of the inversion mutations are suffered mainly by males,and uncommonly by females due to the intra chromosomal recombination among the homologous areas, in inversion 1 or 22, with extragenic copy posited the telomeric to the Factor VIII gene. Unfortunately, there is an absence in Iraq on researches pertaining blood affliction gene identification in persons who carries the Intron22 mutations exception in the current research.Aims of study:The objectives of the research is to to analyze through the detection mechanisms, the existence of Intron 22 mutations in the Factor VIII gene of 10 Hemophilia A Iraqi carriers cohort families. The hypothesis and anticipated result is that there will be a minimal margin of hazardous possibility for the recurrence. The hereditary F8 mutation is unknown to be present on the maternal side of the patient sufferer due to the possibilty of germline mosaics that exists within the community.


Blood ◽  
1994 ◽  
Vol 84 (7) ◽  
pp. 2197-2201 ◽  
Author(s):  
PV Jenkins ◽  
PW Collins ◽  
E Goldman ◽  
A McCraw ◽  
A Riddell ◽  
...  

Abstract Intrachromosomal recombinations involving F8A, in intron 22 of the factor VIII gene, and one of two homologous regions 500 kb 5′ of the factor VIII gene result in large inversions of DNA at the tip of the X chromosome. The gene is disrupted, causing severe hemophilia A. Two inversions are possible, distal and proximal, depending on which homologous region is involved in the recombination event. A simple Southern blotting technique was used to identify patients and carriers of these inversions. In a group of 85 severe hemophilia A patients, 47% had an inversion, of which 80% were of the distal type. There was no association with restriction fragment length polymorphism (RFLP) haplotypes. The technique has identified a definitive genetic marker in families previously uninformative on RFLP analysis and provided valuable information for genetic counselling information may now be provided for carriers without the need to study intervening family members and the diagnosis of severe hemophilia A made in families with only a nonspecific history of bleeding. Analysis of intron 22 inversion should now be the first-line test for carrier diagnosis and genetic counselling for severe hemophilia A and may be particularly useful when there is no affected male family member or when intervening family members are unavailable for testing.


1994 ◽  
Vol 3 (7) ◽  
pp. 1035-1039 ◽  
Author(s):  
Judith Pratt Rosslter ◽  
Michele Young ◽  
Michelle L. Kimberland ◽  
Pierre Hutter ◽  
Rhett P. Ketterling ◽  
...  

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3093-3093
Author(s):  
Joan Cox Gill ◽  
Karen Stephany ◽  
Craig Helsell

Abstract The recent availability of highly purified recombinant coagulation factor concentrates to treat hemorrhages in hemophilic patients is thought to circumvent perturbations in immune function by preventing chronic intravenous exposure to multiple foreign protein antigens. We previously reported a PHA-induced IFN-γ secretion defect in severe hemophilia A patients who had been exposed exclusively to highly purified coagulation factor VIII concentrates. We now report the results of cytokine secretion in response to PHA in cultured PBMCs from severe hemophilia A patients never exposed to FVIII concentrates. PBMCs were isolated from whole blood from three severe HA patients, 3 age-matched normal boys, 3 boys with severe hemophilia B and an adult control. Cells were stained with PKH26 (Sigma), a fluorescent dye with aliphatic tails that intercalate into membrane lipids; cells were than washed and cultured in complete media in wells of microtiter plates with and without PHA. Cells were harvested at 5 days and proliferation detected by loss of membrane PKH26 staining detected by flow cytometry. Cytokines secreted into the supernatants of 48 hour and 5 day cultures were measured by ELISA assays (BD Pharmingen). PBMCs from severe HA patients proliferated normally in response to PHA but failed to secrete IFN-γ when compared to normal boys and boys with severe HB: PBMC Proliferation and Secretion of IFN-γ in Response to PHA Subject Group HA HB Normal Boys Adult Control PHA Proliferation (% unstained cells) M± 1SD 79.3 ±3.7 78.2±13.3 95.4±1.5 89.3±5.3 INF-γ Secretion (pg/mL) M± 1 SD 6.7±4.7 429.0±464 69.1±32.4 770.1±148.7 The severe HA patients did not have improvement in INF-γ secretion following therapeutic exposure to FVIII concentrates. Addition of physiologic concentrations of FVIII or FIX to cultures with or without PHA did not alter the results of proliferation or cytokine secretion regardless of the inhibitor history of the patients. (1 HA and 1 HB patient developed high responder inhibitors.) Secretion of IL-4, IL-5 and IL-10 were moderately decreased in some HA patients as well. In summary, we have confirmed an INF-γ secretion defect in PBMCs from patients with HA in spite of normal proliferation in response to PHA. The defect is not present in HB or normal age-matched control subjects and is not corrected by addition of FVIII to cultures. We conclude that the defect is not due to exposure to intravenous foreign antigens. The precise clinical significance and any possible relation to the higher risk of inhibitor development in HA will require further investigation. PBMC Proliferation and Secretion of IFN-γ in Response to PHA Subject Group HA HB Normal Boys Adult Control PHA Proliferation (% unstained cells) M± 1SD 79.3 ±3.7 78.2±13.3 95.4±1.5 89.3±5.3 INF-γ Secretion (pg/mL) M± 1 SD 6.7±4.7 429.0±464 69.1±32.4 770.1±148.7


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 513-513
Author(s):  
Kyoichi Ogata ◽  
Steven W. Pipe

Abstract Hemophilia A results from the quantitative or qualitative deficiency of coagulation factor VIII (FVIII). FVIII is synthesized as a single-chain polypeptide of approximately 280 kDa with the domain structure A1-A2-B-A3-C1-C2. Whereas the A and C domains exhibit ~40% amino acid identity to each other and to the A and C domains of coagulation factor V, the B domain is not homologous to any known protein and is dispensable for FVIII cofactor activity. Missense mutations in the FVIII B domain have been described in patients with variable phenotypes of hemophilia A. According to the NCBI SNPs (single nucleotide polymorphism) database, 22 SNPs are reported within FVIII, 11 of which occur within the B domain. FVIII B domain variant D1241E has been reported as a missense mutation associated with mild or severe hemophilia A, yet this mutation is also present in the NCBI SNPs database. We hypothesize that D1241E and most other reported B domain missense mutations are not the causative mutation for hemophilia A in these patients but represent SNPs or otherwise non-pathologic mutations. To investigate this, we analyzed 7 B domain missense mutations that were previously found in hemophilia A patients (T751S, V993L, H1047Y, D1241E, T1353A, P1641L and S1669L). Comparative analysis showed that the amino acids at these positions are not conserved in all species and in some cases, the amino acid substitution reported in hemophilia patients is represented in the native sequence in other species. Analysis with PolyPhen Software showed that only H1047Y mutation was considered as “possibly damaging”, while the others were considered as “benign”. To investigate this further, we constructed seven plasmid vectors containing these B domain missense mutations. The synthesis and secretion of FVIII wild-type (WT) and these seven mutants were compared after transient DNA transfection into COS-1 monkey cells in vitro. Analysis of the FVIII clotting activity and antigen levels in the conditioned medium demonstrated that all mutants had FVIII activity and antigen levels similar to FVIII WT. Further, FVIII WT, H1047Y and D1241E mutants were introduced into a FVIII exon 16 knock-out mouse model of hemophilia A by hydrodynamic tailvein injection in vivo. The mouse plasma was analyzed at 24 hrs for activity and antigen expression. Mutants H1047Y and D1241E expressed at 211 mU/mL and 224 mU/mL activity with FVIII antigen levels of 97 ng/mL and 118 ng/mL, respectively, similar to FVIII WT. These results suggested that H1047Y and D1241E mutants did not lead to impairments in secretion or functional activity. We conclude that most missense mutations within the FVIII B domain would be unlikely to lead to severe hemophilia A and that the majority of such missense mutations represent polymorphisms or non-pathologic mutations. Investigators should search for additional potentially causative mutations elsewhere within the FVIII gene when B domain missense mutations are identified.


1998 ◽  
Vol 4 (2) ◽  
pp. 111-113
Author(s):  
Etsuko Yamazaki ◽  
Hiroshi Mohri ◽  
Hiroshi Harano ◽  
Heiwa Kanamori ◽  
Hiroshi Inaba ◽  
...  

Ten patients with severe hemophilia A and 10 with moderate and mild hemophilia A were studied. Five of 10 unrelated patients with severe hemophilia A had the distal telo meric int22h sequence, none had the proximal sequence, and one had a unique variant factor VIII gene rearrangement. Car rier detection was done in these six families. All mothers and two daughters of the patients were to be carriers. Six of the 15 at-risk female relatives were heterozygous for the rearranged and normal allele and were carriers. These results indicate that the rearrangement assay is very useful for carrier detection in families with severe hemophilia A. Key Words: Hemophilia A—Factor VIII gene rearrangement—Genetic counseling.


Sign in / Sign up

Export Citation Format

Share Document