scholarly journals Rare β-Globin Gene Mutations including a de novo Mutation of Hemoglobin Hammersmith in Southern Thailand

2020 ◽  
Author(s):  
Korntip Srewaradachpisal ◽  
Wanicha Tepakhan ◽  
Sataron Kanjanaopas ◽  
Chawadee Nopparatana ◽  
Malai Wongchanchailert ◽  
...  
Keyword(s):  
De Novo ◽  
Globin Gene ◽  
Spontaneous Mutation ◽  
Blot Hybridization ◽  
Point Mutations ◽  
Gene Mutations ◽  
De Novo Mutation ◽  
Dot Blot ◽  
Direct Dna Sequencing ◽  
Southern Thailand

Objective: The aim of this study was to characterize unknown β-globin gene mutations in individuals who attended Songklanagarind Hospital for thalassemia screening and genetic counseling.Material and Methods: β-thalassemia mutations in individuals with hemoglobin (Hb) A2 levels >3.5% originating from various provinces in southern Thailand were characterized by reverse dot blot hybridization (RDB) and multiplex gappolymerase chain reaction using a panel of 30 allele-specific probes for point mutations and 6 sets of specific primers for large deletions. Mutations which could not be identified by these two methods were further analyzed by direct deoxyribonucleic acid (DNA) sequencing.Results: Nineteen subjects found to have uncharacterized β-globin gene mutations were analyzed by direct DNA sequencing. Nine different rare mutations were identified, four of which have not been to date described in Thailand: -30 (T>C), codon 5 (-CT), Hb Monroe (codon 30, G>C) and Hb Hammersmith (codon 42, T>C). An Hb Hammersmith mutation detected in one subject appeared to be a spontaneous mutation, unrelated to family history. The other five mutations have been reported previously within Thailand, but here they were identified in the southern part of Thailand for the first time: -31 (A>G), codon 15 (-T), codon 35 (C>A), codon 95 (+A) and Hb Dhonburi (codon 126, T>G). The presence of the mutations was confirmed by RDB.Conclusion: In addition to the already reported β-globin gene mutations, 9 other different types of mutations were identified. This information should be useful for planning genetic counseling and prenatal diagnosis programs for prevention and control of thalassemia diseases.

scholarly journals SPECTRUM OF BETA GLOBIN GENE MUTATIONS IN EGYPTIAN CHILDREN WITH β- THALASSEMIA

2014 ◽  
Vol 6 (1) ◽  
pp. e2014071 ◽  
Author(s):  
MR El-Shanshory ◽  
Adel Abd Elhaleim Hagag
Keyword(s):  
Dna Sequencing ◽  
Blood Count ◽  
Complete Blood Count ◽  
Globin Gene ◽  
Gene Mutations ◽  
Thalassemia Major ◽  
Direct Dna Sequencing ◽  
Rare Mutations ◽  
Egyptian Children

Background: The molecular defects resulting in β-thalassemia phenotype, in the Egyptian population show a clear heterogenic mutations pattern. PCR based techniques, including direct DNA sequencing are effective on the molecular detection and characterization of these mutations. The molecular characterization of β-thalassemia is absolutely necessary for carrier screening, for genetic counseling, and to offer prenatal diagnosis.The aim of the work: was to evaluate the different β-globin gene mutations in one hundred Egyptian children with β-thalassemia. Patients and Methods: One hundred of β-thalassemic Egyptian children, covering most Egyptian Governorates. All patients were subjected to meticulous history taking, clinical examinations, complete blood count, complete blood count, hemoglobin electrophoresis, serum ferritin and direct fluorescent DNA sequencing of β-globin gene to detect the frequency of different mutations in studied patients. Results: The most common mutations among patients were IVS I-110(G>A) 48%, IVS I-6(T>C) 40%, IVS I-1(G>A)19%,IVS I-5(G>C)10%, IVS II-848 (C>A) 9%, IVS II-745(C>G) 8%, IVS II-1(G>A) 7%, codon"Cd"39(C> T) 4%,-87(C>G) 3% and the rare mutations were: Cd37 (G>A), Cd8 (-AA), Cd29(-G), Cd5 (-CT), Cd6(-A), Cd8/9(+G), Cd 106/107(+G), Cd27(C>T), IVS II-16(G> C), Cd 28 (-C), Cap+1(A>C), -88(C>A), all of these rare mutations were present in 1%. There was considerable variation in phenotypic severity among patients resulting from interaction of different β° and β+mutations, 79(79%) patients were thalassemia major (TM) and 21(21%) were thassemia intermedia (TI), without genotype phenotype association. Conclusion: Direct DNA sequencing provides insights for the frequency of different mutations in β- thalassemic patients including rare and /or unknown ones.

scholarly journals Direct estimate of the spontaneous mutation rate uncovers the effects of drift and recombination in theChlamydomonas reinhardtiiplastid genome

2015 ◽  
Author(s):  
Rob W Ness ◽  
Susanne A Kraemer ◽  
Nick Colegrave ◽  
Peter D Keightley
Keyword(s):  
Mutation Rate ◽  
Genetic Drift ◽  
Plastid Genome ◽  
De Novo ◽  
Spontaneous Mutation ◽  
Genome Structure ◽  
Nuclear Genome ◽  
De Novo Mutation ◽  
Direct Estimate ◽  
Plastid Genomes

Plastids perform crucial cellular functions, including photosynthesis, across a wide variety of eukaryotes. Since endosymbiosis, plastids have maintained independent genomes that now display a wide diversity of gene content, genome structure, gene regulation mechanisms, and transmission modes. The evolution of plastid genomes depends on an input ofde novomutation, but our knowledge of mutation in the plastid is limited to indirect inference from patterns of DNA divergence between species. Here, we use a mutation accumulation experiment, where selection acting on mutations is rendered ineffective, combined with whole-plastid genome sequencing to directly characterize de novo mutation inChlamydomonas reinhardtii. We show that the mutation rates of the plastid and nuclear genomes are similar, but that the base spectra of mutations differ significantly. We integrate our measure of the mutation rate with a population genomic dataset of 20 individuals, and show that the plastid genome is subject to substantially stronger genetic drift than the nuclear genome. We also show that high levels of linkage disequilibrium in the plastid genome are not due to restricted recombination, but are instead a consequence of increased genetic drift. One likely explanation for increased drift in the plastid genome is that there are stronger effects of genetic hitchhiking. The presence of recombination in the plastid is consistent with laboratory studies inC. reinhardtiiand demonstrates that although the plastid genome is thought to be uniparentally inherited, it recombines in nature at a rate similar to the nuclear genome.

scholarly journals A simple approach to prenatal diagnosis of beta-thalassemia in a geographic area where multiple mutations occur

Blood ◽  
1988 ◽  
Vol 71 (5) ◽  
pp. 1357-1360 ◽  
Author(s):  
SP Cai ◽  
JZ Zhang ◽  
DH Huang ◽  
ZX Wang ◽  
YW Kan
Keyword(s):  
Southern China ◽  
Globin Gene ◽  
Blot Hybridization ◽  
Geographic Area ◽  
Simple Approach ◽  
Beta Thalassemia ◽  
Beta Globin ◽  
Dot Blot ◽  
Polymerase Chain

Abstract We describe a simple approach for detecting beta-thalassemia mutations in geographic areas such as southern China where multiple mutations are known to occur. Segments of the beta-globin gene were amplified in vitro by using the polymerase chain reaction. Dot blot hybridization of the amplified DNA with oligonucleotide probes corresponding to the six mutations found in southern China could directly identify the mutations causing beta-thalassemia in the affected families. The increased number of target sequences after amplification allows the use of 35S-labeled probes, which are reusable for up to 3 months. The mutations can be determined in two days.

Mutations in the AML1 Gene Define an Unfavorable Subgroup in Acute Myeloid Leukemia with FAB M0.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4340-4340
Author(s):  
Frank Dicker ◽  
Mirjam Klaus ◽  
Torsten Haferlach ◽  
Wolfgang Kern ◽  
Wolfgang Hiddemann ◽  
...  
Keyword(s):  
High Performance ◽  
De Novo ◽  
Mutation Screening ◽  
Point Mutations ◽  
Gene Mutations ◽  
Normal Karyotype ◽  
Runt Domain ◽  
Screening Efficiency ◽  
Genetic Aberration ◽  
Aml1 Gene

Abstract The AML1/RUNX1 gene is the most frequent target for chromosomal translocations in leukemia. Recently point mutations in the AML1 gene have been demonstrated as another mode of genetic aberration. AML1 mutations have been reported in de novo MDS and AML, as well as in therapy related MDS and AML. The AML M0 subtype has been found to be most frequently affected by sporadic AML1 gene mutations. We analysed AML1 gene mutations in a cohort of 49 M0 patients. Mutation screening was performed either with SSCP (n=21) and/or denaturating High Performance Liquid Chromatography (dHPLC) (n=33), 5 cases were analyzed by both methods. SSCP screening of exons 3–5 of the AML1 gene was carried out at the genomic level. These exons cover the socalled Runt domain, which is most frequently mutated. Fragments with aberrant mobility were sequenced. With this method 5 cases were found to be mutated. Subsequently, to improve the screening efficiency an assay using dHPLC was established. Hereby, we screened the cDNA of patient samples for mutations in amino acid codons 1–277 of the AML1b transcript, where the Runt domain is located between codons 49 and 178. All 5 cases detected by SSCP were confirmed by dHPLC. Nine mutations were detected in the cohort of 28 cases (32%) which had not been analyzed by SSCP. In total, 14 of the 49 samples (29%) tested were identified to be mutated, which is a slightly higher frequency than previously reported. In the cohort of 35 AML1 non-mutated cases 20 (57%) had a normal karyotype and 15 (43%) an aberrant karyotypes, whereas only 6 of the 14 AML1 mutated cases (43%) had a normal karyotype (p=0.001). Three of the AML1 mutated cases (21%) also had FLT3 mutations. One had an FLT3-LM, one an FLT3-TKD mutation, and one case both LM and TKD mutations. Clinical follow up data were available for 33 patients (22 AML1 non- mutated, 11 AML1 mutated). The median OS and EFS of the AML1 non-mutated versus the mutated group was 276 days versus 63 days (p = 0.0679) and 276 vs. 63 days (p=0.0630) respectively. Thus the AML1 mutated cases tend to have a worse clinical outcome. When other AML subtypes were screened for AML1 mutations, i.e. M1 (n=26), M2 (n=21) and M4 (n=3), only 1 additional AML1 mutation was detected, confirming the highest prevalence of AML1 mutations in M0. In conclusion, 1) we established a new assay to screen for AML1 mutations. 2) We confirmed the high incidence of AML1 gene mutations in AML M0, both in cases with normal and aberrant karyotype. 3) For the first time we demonstrated that AML1 mutations define an unfavorable subentity in AML M0.

scholarly journals Rapid and simultaneous typing of hemoglobin S, hemoglobin C, and seven Mediterranean beta-thalassemia mutations by covalent reverse dot-blot analysis: application to prenatal diagnosis in Sicily

Blood ◽  
1993 ◽  
Vol 81 (1) ◽  
pp. 239-242 ◽  
Author(s):  
A Maggio ◽  
A Giambona ◽  
SP Cai ◽  
J Wall ◽  
YW Kan ◽  
...  
Keyword(s):  
Globin Gene ◽  
Blot Hybridization ◽  
Beta Thalassemia ◽  
Dot Blot ◽  
Hemoglobin C ◽  
Mediterranean Regions ◽  
Analysis Application ◽  
Working Day ◽  
Dot Blot Analysis ◽  
Reverse Dot Blot

Abstract The molecular lesions causing beta-thalassemia in Sicily can be subdivided into two groups. One that occurs at a 71% frequency and consists of the beta 39, IVS 1,110 and IVS 1,6 mutations and the other group at a 20% frequency comprising the -87, beta s, IVS 1,1 and IVS 2,745 mutations. The identification of all these mutations by polymerase chain reaction (PCR) and conventional dot-blot hybridization has been time consuming and expensive. In this article, we describe the implementation of the reverse dot-blot (RDB) hybridization as a rapid nonradioactive method for the identification of the nine most frequent molecular lesions in the beta-globin gene (-87, beta s, beta c, IVS 1,1, IVS 1,6, IVS 1,110, beta 39, IVS 2,1, IVS 2,745) in Sicily. Sixty prenatal diagnoses were performed by this RDB assay, each of which was confirmed by dot-blot/ASO hybridization; thus demonstrating the accuracy of the RDB. The main advantage of this assay is the rapid typing of an individual's DNA for many mutations in a single working day. Because the mutations in this assay are representative for the Mediterranean region, this mutational panel can also be extended to the screening of beta-thalassemia from other Mediterranean regions.

scholarly journals Direct estimation of the spontaneous mutation rate by short-term mutation accumulation lines in Chironomus riparius

2016 ◽  
Author(s):  
Ann-Marie Oppold ◽  
Markus Pfenninger
Keyword(s):  
Mutation Rate ◽  
De Novo ◽  
Spontaneous Mutation ◽  
Single Point ◽  
Point Mutations ◽  
Mutation Accumulation ◽  
Occurrence Rate ◽  
Spontaneous Mutation Rate ◽  
Biting Midge ◽  
Mutational Spectrum

AbstractMutations are the ultimate basis of evolution, yet their occurrence rate is known only for few species. We directly estimated the spontaneous mutation rate and the mutational spectrum in the non-biting midge C. riparius with a new approach. Individuals from ten mutation accumulation lines over five generations were deep genome sequenced to count de novo mutations (DNMs) that were not present in a pool of F1 individuals, representing parental genotypes. We identified 51 new single site mutations of which 25 were insertions or deletions and 26 single point mutations. This shift in the mutational spectrum compared to other organisms was explained by the high A/T content of the species. We estimated a haploid mutation rate of 2.1 x 10−9 (95% confidence interval: 1.4 x 10−9 – 3.1 x 10−9) which is in the range of recent estimates for other insects and supports the drift barrier hypothesis. We show that accurate mutation rate estimation from a high number of observed mutations is feasible with moderate effort even for non-model species.

scholarly journals Analysis of beta globin gene mutations in Diyarbakir

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Selahaddin Tekeş ◽  
Diclehan Oral ◽  
Murat Söker ◽  
Selda Şimşek ◽  
Veysiye Hülya Uzel ◽  
...  
Keyword(s):  
Globin Gene ◽  
Molecular Genetic ◽  
Point Mutations ◽  
Gene Mutations ◽  
Turkish Population ◽  
University Hospital ◽  
Beta Thalassemia ◽  
Amplification Refractory Mutation System ◽  
Compound Heterozygous ◽  
Common Mutation

Abstract Objectives Hemoglobin disorders are quite heterogeneous in the Turkish population. Up to now, more than forty different beta thalassemia mutations and 60 hemoglobin variants have been characterized in the country. The aim of this study was to investigate genetic heterogeneity of HBB gene mutations in patients and their parents at Southeastern Anatolia in Turkey. Methods Genomic DNA was isolated from 145 thalassemic patients’ blood samples and their parents in this study. Ten different HBB gene mutations HBB:c.-80T>A, HBB:c.17_18delCT, HBB:c.25_26delAA, HBB:c.92+1G>A, HBB:c.92+5G>C, HBB:c.92+6T>C, HBB:c.93-21G>A, HBB:c.135delC, HBB:c.315+1G>A, HBB:c.316-106C>G were screened by amplification refractory mutation system. Four Hb variants and some rare beta thalassemia mutation were characterized by DNA sequencing. Results In this study, 97 homozygous and 48 compound heterozygous thalassemic patients were diagnosed by molecular genetic analyses. As a results, 18 β-thalassemia mutations and four abnormal hemoglobins; HBB:c.20A>T, HBB:c.364G>C, HBB:c.34G>A and HBB:c.208G>A were detected at Dicle University Hospital. Conclusions In the results, HBB:c.93-21G>A is the most common mutation in the region. Three mutations [(HBB:c.93-21G>A), (HBB:c.25_26delAA) and (HBB:c.135delC)] account for about 58 per cent of all the point mutations. Except HBB:c.20A>T and HBB:c.364G>C, two silent Hb variants (HBB:c.34G>A and HBB:c.208G>A) were detected in this study. Hb Hamilton [β11 (GTT>ATT) Val>Ile] was seen first time in Turkey.

scholarly journals A natural regulatory mutation in the proximal promoter elevates fetal globin expression by creating a de novo GATA1 site

Blood ◽  
2019 ◽  
Vol 133 (8) ◽  
pp. 852-856 ◽  
Author(s):  
Gabriella E. Martyn ◽  
Beeke Wienert ◽  
Ryo Kurita ◽  
Yukio Nakamura ◽  
Kate G. R. Quinlan ◽  
...  
Keyword(s):  
Binding Site ◽  
De Novo ◽  
Globin Gene ◽  
Point Mutations ◽  
Fetal Hemoglobin ◽  
Proximal Promoter ◽  
Genetic Condition ◽  
Regulatory Mutation ◽  
Hereditary Persistence ◽  
Globin Promoter

Abstract β-hemoglobinopathies, such as sickle cell disease and β-thalassemia, result from mutations in the adult β-globin gene. Reactivating the developmentally silenced fetal γ-globin gene elevates fetal hemoglobin levels and ameliorates symptoms of β-hemoglobinopathies. The continued expression of fetal γ-globin into adulthood occurs naturally in a genetic condition termed hereditary persistence of fetal hemoglobin (HPFH). Point mutations in the fetal γ-globin proximal promoter can cause HPFH. The −113A>G HPFH mutation falls within the −115 cluster of HPFH mutations, a binding site for the fetal globin repressor BCL11A. We demonstrate that the −113A>G HPFH mutation, unlike other mutations in the cluster, does not disrupt BCL11A binding but rather creates a de novo binding site for the transcriptional activator GATA1. Introduction of the −113A>G HPFH mutation into erythroid cells using the clustered regularly interspaced short palindromic repeats (CRISPR)–CRISPR-associated protein 9 (Cas9) system increases GATA1 binding and elevates fetal globin levels. These results reveal the mechanism by which the −113A>G HPFH mutation elevates fetal globin and demonstrate the sensitivity of the fetal globin promoter to point mutations that often disrupt repressor binding sites but here create a de novo site for an erythroid activator.

scholarly journals Hemoglobin Cagliari (beta 60 [E4] Val----Glu): a novel unstable thalassemic hemoglobinopathy

Blood ◽  
1991 ◽  
Vol 77 (2) ◽  
pp. 371-375 ◽  
Author(s):  
A Podda ◽  
R Galanello ◽  
L Maccioni ◽  
MA Melis ◽  
C Rosatelli ◽  
...  
Keyword(s):  
Structural Analysis ◽  
Peripheral Blood ◽  
De Novo ◽  
Globin Gene ◽  
De Novo Mutation ◽  
Beta Globin ◽  
Globin Chain ◽  
Thalassemia Intermedia ◽  
Protein Structural Analysis ◽  
Chain Synthesis

Abstract This report describes a patient with thalassemia intermedia-like phenotype born to normal parents in whom globin gene sequencing detected a novel abnormal hemoglobin (Hb) due to a T to A substitution at codon 60 of the beta-globin gene arising as a de novo mutation. Normal sequences were detected at the homologous beta-globin locus. This mutation results in the substitution of a polar (glutamic acid) for a nonpolar (valine) residue near the corner of the heme pocket of the beta-globin chain. The novel variant has been designated Hb Cagliari, from the place of birth of the propositus. Kinetics of globin synthesis performed following splenectomy suggest that this new Hb variant is synthesized at a near normal rate but undergoes rapid breakdown. The extreme lability of the variant explains the clinical and hematologic picture characterized by marked ineffective erythropoiesis, thalassemia-like bone changes, iron overload, high proportion of Hb F in the peripheral blood, reduced beta/alpha-globin chain synthesis ratio in peripheral blood reticulocytes, and absence of the abnormal Hb in peripheral blood at extensive protein structural analysis before splenectomy. This case indicates that a thalassemic hemoglobinopathy should be suspected in the presence of a patient with a thalassemia intermedia-like phenotype born to normal parents, even when protein structural analysis fails to detect an abnormal Hb. DNA sequencing may allow to define the mutation, thus making the proper diagnosis.

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