Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 453
Filtrar
1.
Med Sci Monit Basic Res ; 27: e929207, 2021 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-33397841

RESUMO

As of November 25, 2020, over 60 million people have been infected worldwide by COVID-19, causing almost 1.43 million deaths. Puzzling low incidence numbers and milder, non-fatal disease have been observed in Thailand and its Southeast (SE) Asian neighbors. Elusive genetic mechanisms might be operative, as a multitude of genetic factors are widely shared between the SE Asian populations, such as the more than 60 different thalassemia syndromes (principally dominated by the HbE trait). In this study, we have plotted COVID-19 infection and death rates in SE Asian (SEA) countries against heterozygote HbE and thalassemia carrier prevalence. COVID-19 infection and death incidence numbers appear inversely correlated with the prevalence of HbE and thalassemia heterozygote populations. We posit that the evolutionary protective effect of the HbE and other thalassemic variants against malaria and the dengue virus may extend its advantage to resistance to COVID-19 infection, as HbE heterozygote population prevalence appears to be positively correlated with immunity to COVID-19. Host immune system modulations induce antiviral interferon responses and alter structural protein integrity, thereby inhibiting cellular access and viral replication. These changes are possibly engendered by HbE carrier miRNAs. Proving this hypothesis is important, as it may shed light on the mechanism of viral resistance and lead to novel antiviral treatments. This development can thus guide decision-making and action to prevent COVID-19 infection.


Assuntos
/genética , Resistência à Doença/genética , Suscetibilidade a Doenças , Hemoglobina E/genética , Antivirais/uso terapêutico , Grupo com Ancestrais do Continente Asiático , /imunologia , Dengue/genética , Heterozigoto , Humanos , Sistema Imunitário , Interferons , Malária/genética , Pandemias , Prevalência , Tailândia/epidemiologia , Talassemia/epidemiologia , Talassemia/genética
2.
Ann Hematol ; 99(4): 729-735, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32078010

RESUMO

HbE/Beta thalassemia (HbE/ß-thalassemia) is one of the common genetic disorders in South East Asia. It is heterogeneous in its clinical presentation and molecular defects. There are genetic modifiers which have been reported to influence the disease severity of this disorder. The aim of this study was to determine the genetic polymorphisms which were responsible for the disease clinical diversity. A case-control study was conducted among Malay transfusion-dependent HbE/ß-thalassemia patients. Patients who were confirmed HbE/ß-thalassemia were recruited and genotyping study was performed on these subjects. Ninety-eight patients were selected and divided into moderate and severe groups based on clinical parameters using Sripichai scoring system (based on hemoglobin level, spleen size, growth development, the age of first transfusion and age of disease presentation). Forty-three (44.9%) and 55 (56.1%) patients were found to have moderate and severe clinical presentation, respectively. Genotyping analysis was performed using Affymetrix 6.0 microarray platform. The SNPs were filtered using PLINK and Manhattan plot by R software. From the GWAS results, 20 most significant SNPs were selected based on disease severity when compared between moderate and severe groups. The significant SNPs found in this study were mostly related to thalassemia complications such as rs7372408, associated with KCNMB2-AS1 and SNPs associated with disease severity. These findings could be used as genetic predictors in managing patients with HbE/ß-thalassemia and served as platform for future study.


Assuntos
Hemoglobina E/genética , Hemoglobinúria/genética , Polimorfismo de Nucleotídeo Único , Globinas beta/genética , Talassemia beta/genética , Estudos de Casos e Controles , Criança , Grupos Étnicos/genética , Feminino , Estudos de Associação Genética , Estudo de Associação Genômica Ampla , Heterozigoto , Humanos , Malásia , Masculino , Fenótipo , Índice de Gravidade de Doença
3.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 37(1): 33-36, 2020 Jan 10.
Artigo em Chinês | MEDLINE | ID: mdl-31922592

RESUMO

OBJECTIVE: To explore hematological and genotypic characteristics of patients with hemoglobin E (Hb E) disorders from Yunnan Province. METHODS: One hundred individuals with Hb E disorders indicated by high performance liquid chromatography (HPLC) were subjected to genetic testing through multiple gap-PCR and reverse dot-blotting analysis. RESULTS: All patients were found to harbor a mutation to the 26th codon of the ß -globin chain (HBB: c.79G>A). Ninety patients were heterozygotes, and 10 co-inherited c.79G>A and an α -thalassemia mutation (7 α α /-α3.7, 2 α α /--SEA and 1 -α 3.7/-α3.7). Hematological characteristics of the heterozygotes were: Hb A2 (26.02±3.64)%, Hb F(1.35±1.25)%, MCV(78.83±4.68) fl, MCH(26±1.54) pg, MCHC (329.65±10.73) g/L, HGB (141.08±16.53) g/L, while that of the co-inherited cases was decided by the type of α -thalassemia mutation. CONCLUSION: Hb E can be effectively detected by HPLC. The type of α -thalassemia mutations will determine hematological features of co-inherited cases. Hb E disorders may be missed by relying only on routine blood test upon prenatal screening.


Assuntos
Hemoglobina E , Talassemia alfa , China , Feminino , Genótipo , Hemoglobina E/genética , Humanos , Mutação , Gravidez , Talassemia alfa/genética , Globinas beta/genética
4.
Pak J Biol Sci ; 23(1): 17-26, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31930879

RESUMO

BACKGROUND AND OBJECTIVES: Hemoglobin E is a variant hemoglobin caused due to the base substitution G→A at codon 26 in the ß-globin-coding gene that is followed by the alteration of glutamic acid (GAG) to lysine (AAG). Various types of molecular analysis methods such as tetra-primer amplification refractory mutation system (T-ARMS-PCR), Tm-shift real-time polymerase chain reaction (Tm-shift qPCR) and high-resolution melting analysis (HRMA) are commonly used to detect several mutations in the ß-globin-coding gene. This study was conducted to compare the detection result of Cd 26 (G→A) mutation in the ß-globin-coding gene of heterozygous HbE between the above-mentioned methods. MATERIALS AND METHODS: DNA samples were isolated from blood archive of heterozygous HbE and analyzed for the detection of the mutation using HRMA and Tm-shift on a real-time PCR instrument, whereas T-ARMS analysis was performed on a conventional PCR equipment. High resolution melt v3.1 software and Bio-Rad CFX Manager software were used to analyze the result of HRMA and Tm-shift qPCR, whereas the T-ARMS-PCR result was analyzed by observing the number and size of DNA bands on gel electrophoresis. RESULTS: Among 21 samples, the Cd 26 mutation was detected in numbers 18, 19 and 21 by HRMA, Tm-shift qPCR and T-ARMS-PCR. DNA Sequencing confirmed Cd 26 mutation on 5 ambiguous samples and revealed two homozygous mutation. CONCLUSION: The Cd 26 (G→A) mutation was detected in proportions 100, 91 and 86% by T-ARMS-PCR, Tm-shift qPCR and HRMA, respectively.


Assuntos
Hemoglobina E/genética , Patologia Molecular/métodos , Sequência de Bases , Hemoglobina E/metabolismo , Heterozigoto , Homozigoto , Humanos , Mutação , Reação em Cadeia da Polimerase
5.
Ann Hematol ; 99(1): 23-29, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31776727

RESUMO

Hemoglobin (Hb) F has a modulatory effect on the clinical phenotype of ß-thalassemia disease. High expression of Hb F in Hb E-related disorders has been noted, but the mechanism is not well understood. We have examined the association of a novel SNP rs11759328 on ARHGAP 18 gene and other known modulators with a variability of Hb F in Hb E-related disorders. Genotyping of SNP rs11759328 (G/A) was performed based on high-resolution melting analysis. The rs11759328 (A allele) was shown to be significantly associated with Hb F levels (p < 0.05) in heterozygous and homozygous Hb E. High levels of Hb F in both heterozygous and homozygous Hb E were also found to be associated with SNPs in the study of other modifying genes including KLF 1 mutation, rs7482144 (Gγ-XmnI), rs4895441, rs9399137 of (HBS1L-MYB), and rs4671393 (BCL11A). Multivariate analysis showed that KLF1 mutation and SNP rs11759328 (GA) (ARHGAP18) modulated Hb F expression in heterozygous Hb E. For homozygous Hb E, this was found to be related to five modifying factors, i.e., KLF1 mutation, rs4895441 (GG), rs9399137 (CC), rs4671393 (AA), and rs4671393 (GA). These results indicate that a novel SNP rs11759328 is a genetically modifying factor associated with increased Hb F in Hb E disorder.


Assuntos
Hemoglobina Fetal/biossíntese , Proteínas Ativadoras de GTPase/genética , Regulação da Expressão Gênica , Hemoglobinúria/genética , Mutação , Polimorfismo de Nucleotídeo Único , Hemoglobina Fetal/genética , Proteínas Ativadoras de GTPase/metabolismo , Hemoglobina E/genética , Hemoglobina E/metabolismo , Hemoglobinúria/sangue , Humanos , Fatores de Transcrição Kruppel-Like/genética , Fatores de Transcrição Kruppel-Like/metabolismo , Tailândia
6.
Ann Clin Lab Sci ; 49(6): 804-809, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31882432

RESUMO

OBJECTIVE: Hemoglobin E (Hb E) possesses an influence on HbA1c levels. Careful interpretation of HbA1c is needed in areas with a high prevalence of Hb E, including Thailand. Therefore, the normal levels of HbA1c in non-diabetic Hb E subjects were collected and assessed. METHODS: A cross-sectional study was conducted in Hb E subjects aged 18 years and above (N=70). An oral glucose tolerance test was performed. HbA1c levels were measured with 3 assays: ion exchange HPLC, immunoassay (ImmA), and enzymatic assay (EnzA). Individuals who received regular blood transfusions and diabetic patients were excluded. RESULTS: Among 34 subjects with heterozygous Hb E (EA), the mean (±SD) HbA1c levels by HPLC, ImmA, and EnzA were 5.63±0.55%, 4.73±0.62%, and 5.29±0.37%, respectively. Among 29 subjects with homozygous Hb E (EE), the mean (±SD) HbA1c levels by HPLC, ImmA, and EnzA were 3.37±0.69%, 4.37±0.76, and 4.91±0.28%, respectively. Immunoassay and enzymatic methods seem preferable over HPLC for this population. The HbA1c level of 5.7 (99th percentile) from immunoassay is a proposed cut-off point for detecting individuals who are at an increased risk of diabetes. CONCLUSION: There are subjects with hemoglobin E whose HbA1c levels are deemed inaccurate due to the techniques used. Within this study normal HbA1c levels were determined by 3 different assays. The HbA1c level of 5.7 by immunoassay (Advia, 1600) is proposed as the cut-off point for diagnosing subjects at risk of diabetes.


Assuntos
Hemoglobina A Glicada/análise , Hemoglobina E/análise , Adulto , Análise Química do Sangue/métodos , Estudos Transversais , Diabetes Mellitus/sangue , Feminino , Hemoglobina E/genética , Heterozigoto , Homozigoto , Humanos , Imunoensaio , Masculino , Pessoa de Meia-Idade , Valores de Referência
7.
Indian J Med Res ; 150(2): 161-166, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31670271

RESUMO

Background & objectives: Swiss-type hereditary persistence of foetal haemoglobin (HPFH) has been shown to be responsible for the wide range of F cell levels in healthy Thai adults. However, a survey for F cells in healthy Thai adults has not been performed. This study was conducted to determine the F cell distribution in adult Thai blood donors and to assess the possible involvement of ß-thalassaemia and haemoglobin E (HbE) carriers in increased HbF levels. Methods: Thai blood donors (n=375, 205 males and 170 females) were included in the study. Blood samples were collected for measuring haemoglobin (Hb) concentration and haematocrit (Hct) and F cell levels. Hb and Hct levels were determined by automated blood counter, while F cells were quantified by flow cytometric analysis of F cells stained by fluorescein isothiocyanate-conjugated anti γ-globin monoclonal antibody. Finally, F cell levels were compared between blood samples having mean corpuscular volume (MCV ) <80 fl and ≥80 fl as well as between ß-haemoglobinopathies (HbE and ß-thalassaemia carriers) and normal adults. Results: F cell levels varied markedly spanning 0.80-39.2 per cent with a positively skewed distribution. Thirty two per cent of these individuals had F cell levels more than the 4.5 per cent cut-off point. F cell levels in females were significantly higher than those in males (P<0.05). F cell levels in individuals having MCV <80 fl were significantly higher than those having MCV ≥80 fl (P<0.05). ß-haemoglobinopathy (HbE and ß-thalassaemia carriers) had significantly higher F cell levels than normal individuals (P<0.05). Interpretation & conclusions: The present results showed that besides Swiss-type HPFH, the ß-haemoglobinopathy was expected to be involved in increased F cell levels in adult Thais. Thus, influence of ß-haemoglobinopathy must be considered in interpreting F cell levels in area endemic of this globin disorder.


Assuntos
Hemoglobina Fetal/genética , Hemoglobina E/genética , Hemoglobinopatias/genética , Talassemia beta/genética , Adulto , Anemia Falciforme/sangue , Anemia Falciforme/epidemiologia , Anemia Falciforme/genética , Anemia Falciforme/patologia , Doadores de Sangue , Pré-Escolar , Índices de Eritrócitos/genética , Feminino , Hemoglobinopatias/sangue , Hemoglobinopatias/epidemiologia , Hemoglobinopatias/patologia , Heterozigoto , Humanos , Lactente , Recém-Nascido , Masculino , Fenótipo , Tailândia , Talassemia beta/sangue , Talassemia beta/epidemiologia , Talassemia beta/patologia
8.
PLoS One ; 14(11): e0225457, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31751397

RESUMO

Thalassemia and hemoglobinopathy is a group of hereditary blood disorder with diverse clinical manifestation inherited by autosomal recessive manner. The Beta thalassemia/Hemoglobin E disease (HbE/ßthal) causes a variable degree of hemolysis and the most severe form of HbE/ßthal disease develop a lifelong transfusion-dependent anemia. Preimplantation genetic testing (PGT) is an established procedure of embryo genetic analysis to avoid the risk of passing on this particular condition from the carrier parents to their offspring. Preimplantation genetic testing for chromosomal aneuploidy (PGT-A) also facilitates the selection of embryos without chromosomal aberration resulting in the successful embryo implantation rate. Herein, we study the clinical outcome of using combined PGT-M and PGT-A in couples at risk of passing on HbE/ßthal disease. The study was performed from January 2016 to December 2017. PGT-M was developed using short tandem repeat linkage analysis around the beta globin gene cluster and direct mutation testing using primer extension-based mini-sequencing. Thereafter, we recruited 15 couples at risk of passing on HbE/ßthal disease who underwent a combined total of 22 IVF cycles. PGT was performed in 106 embryos with a 3.89% allele drop-out rate. Using combined PGT-M and PGT-A methods, 80% of women obtained satisfactory genetic testing results and were able to undergo embryo transfer within the first two cycles. The successful implantation rate was 64.29%. PGT accuracy was evaluated by prenatal and postnatal genetic confirmation and 100% had a genetic status consistent with PGT results. The overall clinical outcome of successful live birth for couples at risk of producing offspring with HbE/ßthal was 53.33%. Conclusively, combined PGT-M and PGT-A is a useful technology to prevent HbE/ßthal disease in the offspring of recessive carriers.


Assuntos
Testes Genéticos/métodos , Hemoglobina E/genética , Diagnóstico Pré-Implantação/métodos , Globinas beta/genética , Talassemia beta/genética , Aneuploidia , Características da Família , Feminino , Fertilização In Vitro/estatística & dados numéricos , Humanos , Masculino , Repetições de Microssatélites , Mutação , Gravidez , Estudos Retrospectivos , Análise de Sequência de DNA
9.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 27(5): 1580-1584, 2019 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-31607315

RESUMO

OBJECTIVE: To analyze the hematological characteristics of HbE homozygotes. METHODS: Complete blood cells count and hemoglobin electrophoresis were used for phenotypic analysis of 78 cases with HbE homozygotes from Yunnan province, China. The PCR-fluorescence hybridization was used to detect the common gene mutation of thalassemia. The hematological indexes, including MCV, MCH, Hb, HbA2, HbF and HbE were statistically analyzed between groups with different sex, ages and compound α thalassemia status. RESULTS: In HbE homozygotes (HbEE), 89.5% (17/19) children presented mild to moderate microcytic hypochromic anemia, and 10.5% of them presented moderate anemia. 39.6% (19/48) of women with HbEE developed mild anemia ,while 11 cases of male with HbE homozygotes were asymptomatic. The levels of MCV and MCH in HbE homozygotes increased by co-inheritance of α thalassemia mutation. CONCLUSION: The clinical phenotype of HbE homozygote shows highly heterogeneous, which is relates with age, sex and co-inheriting α-globin genotypes. In Hb EE women and children are more likely to develop mild to moderate anemia. The microcytic hypochromic anemia degree is relieved when HbEE combined with α- thalassemia.


Assuntos
Hemoglobina E/genética , Criança , China , Feminino , Genótipo , Homozigoto , Humanos , Masculino , Fenótipo , Talassemia alfa
10.
Hemoglobin ; 43(3): 214-217, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31450984

RESUMO

We report the molecular and hematological identifications of a Hb A2 variant [coinheritance of Hb A2-Melbourne (HBD: c.130G>A) and Hb E (HBB: c.79G>A)] found for the first time in the Lao People's Democratic Republic (PDR). The subject was a 29-year-old pregnant Laotian woman who was a foreign worker in Thailand and was diagnosed with thalassemia and hemoglobinopathies. Capillary electrophoresis (CE) demonstrated 1.6% of Hb A2, with a minor unknown peak at the initial Z1 zone (1.7%). Identification of abnormal hemoglobin (Hb) using direct DNA sequencing showed a genetic defect causing a δ-globin gene missense mutation at codon 43 (GAG>AAG) causing a glutamic acid to lysine substitution corresponding to Hb A2-Melbourne. The origin of Hb A2-Melbourne in Lao PDR may be similar to a case found in Thailand with the [+ - - - - + +] haplotype. We developed a method that could clearly detect Hb A2-Melbourne and Hb A2-Lampang (HBD: c.142G>A) mutations in a single tube using high resolution melt (HRM) analysis. The HRM analysis is a more effective method for rapid detection than conventional polymerase chain reaction (PCR), as there is no need for a post-PCR step, and no exposure to ethidium bromide. This new method would be a useful addition for the first investigation of a suspected Hb A2 variant in the routine molecular setting.


Assuntos
Alelos , Genótipo , Hemoglobina E/genética , Hemoglobinas Anormais/genética , Padrões de Herança , Mutação , Biomarcadores , Análise Mutacional de DNA , Índices de Eritrócitos , Feminino , Hemoglobinopatias/diagnóstico , Hemoglobinopatias/genética , Humanos , Laos , Reação em Cadeia da Polimerase , Gravidez
11.
Pediatr Hematol Oncol ; 36(6): 394-398, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31424305

RESUMO

Hemoglobin Köln, is the most common unstable hemoglobin variant worldwide, yet has only rarely been reported in Indians. Herein we report a case of coinheritance of Hb Köln and Hb E, which to the best of our knowledge has not been reported in the literature so far. The patient presented with mild symptoms of hemolysis with no previous history of blood transfusions.


Assuntos
Hemoglobina E/genética , Hemoglobinas Anormais/genética , Pré-Escolar , Humanos , Índia , Masculino
12.
Int J Lab Hematol ; 41(5): 650-656, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31271507

RESUMO

INTRODUCTION: Thalassemias and hemoglobinopathies are the most prevalent inherited anemias detected in South East Asians. These disorders represent not only a clinical health problem but also a socioeconomic problem for this region. Regarding the prevention and control of thalassemias and hemoglobinopathies in the Lao PDR, screening and diagnostic strategies should be strongly considered. The knowledge about the prevalence and molecular genotyping of thalassemias and hemoglobinopathies among the Lao Loum group, which includes the majority of Lao people, is now limited, making the prevention and control of thalassemias difficult. METHODS: This study aimed to determine the prevalence of thalassemia among Lao Loum subjects of reproductive age. Multiplex gap PCR and direct sequencing were used to investigate the mutations of α-globin and ß-globin genes. RESULTS: Thalassemias and hemoglobinopathies were detected in 154 of 354 (43.50%) patients, and 22 different genotypes were identified in this cohort. Remarkably, high frequencies of hemoglobin E, α0 -thalassemia (--SEA ), and α+ -thalassemia (-α3.7 ) were noted. A variety of hematologic features was observed, including co-inheritance of heterozygous HbE and heterozygous α-thalassemia, which was associated with significantly lower levels of MCV and MCH values than those observed in typical HbE heterozygotes. Female participants who were heterozygous for ß0 or co-inheritance of heterozygous ßE with heterozygous α-thalassemia exhibited mild anemia. CONCLUSION: Our data show that thalassemias and hemoglobinopathies have become health problems imposing a serious burden in the Lao PDR. Prevention programs aimed at decreasing the incidence of severe thalassemia diseases should be designed and initiated.


Assuntos
Hemoglobina E/genética , Hemoglobinopatias/genética , Mutação , alfa-Globinas/genética , Talassemia alfa/genética , Talassemia beta/genética , Adolescente , Feminino , Frequência do Gene , Testes Genéticos/métodos , Genótipo , Hemoglobinopatias/diagnóstico , Hemoglobinopatias/epidemiologia , Humanos , Laos/epidemiologia , Masculino , Prevalência , Adulto Jovem , Talassemia alfa/diagnóstico , Talassemia alfa/epidemiologia , Talassemia beta/diagnóstico , Talassemia beta/epidemiologia
13.
Ann Hematol ; 98(8): 1827-1834, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31190133

RESUMO

In this study, we aimed to investigate the pattern and association of genetic mutations occurring within the alpha hemoglobin-stabilizing protein (AHSP) gene among HbE beta thalassemia patients with varying phenotypic expressions. Fifty-four diagnosed cases of HbE beta thalassemia (transfusion dependent and independent) were included in the study. Among them, 38 patients with similar genotypes (IVS 1-5, alpha gene deletion and triplication, Xmn polymorphism) were selected for further analysis. AHSP gene sequencing was done for these 38 samples to study associated mutations in AHSP gene. HbE beta thalassemia patients with similar genotypes but different phenotypic expressions were found to have mutations in the AHSP gene. There were five mutations found most prevalent among the samples analyzed for AHSP gene sequencing. Among these, two mutations were from intron 1 region of AHSP and three mutations were found in exon 3. The most prevalent mutation was found at the Oct binding site at intron 1 of AHSP. The mutations in exon 3 were more prevalent among the TDT groups. A mutation in exon 3 changing the amino acid (33rd) from serine to phenylalanine was found to be associated with only TDT group. This study documents that among the HbE beta thalassemia patients with varying severity, an exon mutation in AHSP is significantly prevalent only among the TDT group. Further understanding of the mechanism will shed light upon the impact of AHSP in modifying the disease severity in thalassemia.


Assuntos
Proteínas Sanguíneas/genética , Deleção de Genes , Duplicação Gênica , Hemoglobina E/genética , Chaperonas Moleculares/genética , Talassemia beta/genética , Adolescente , Adulto , Sequência de Bases , Proteínas Sanguíneas/metabolismo , Transfusão de Sangue/estatística & dados numéricos , Criança , Pré-Escolar , Análise Mutacional de DNA , Eritrócitos/metabolismo , Eritrócitos/patologia , Éxons , Feminino , Expressão Gênica , Genótipo , Hemoglobina E/metabolismo , Humanos , Íntrons , Masculino , Pessoa de Meia-Idade , Modelos Moleculares , Chaperonas Moleculares/metabolismo , Fenótipo , Estrutura Secundária de Proteína , Índice de Gravidade de Doença , Talassemia beta/metabolismo , Talassemia beta/patologia , Talassemia beta/terapia
14.
Sci Rep ; 9(1): 7672, 2019 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-31113996

RESUMO

A cytosine to thymine mutation at nucleotide 654 of human ß-globin intron 2 (ßIVS2-654) is one of the most common mutations causing ß-thalassaemia in Chinese and Southeast Asians. This mutation results in aberrant ß-globin pre-mRNA splicing and prevents synthesis of ß-globin protein. Splicing correction using synthetic splice-switching oligonucleotides (SSOs) has been shown to restore expression of the ß-globin protein, but to maintain therapeutically relevant levels of ß-globin it would require lifelong administration. Here, we demonstrate long-term splicing correction using U7 snRNA lentiviral vectors engineered to target several pre-mRNA splicing elements on the ßIVS2-654-globin pre-mRNA such as cryptic 3' splice site, aberrant 5' splice site, cryptic branch point and an exonic splicing enhancer. A double-target engineered U7 snRNAs targeted to the cryptic branch point and an exonic splicing enhancer, U7.BP + 623, was the most effective in a model cell line, HeLa IVS2-654. Moreover, the therapeutic potential of the vector was demonstrated in erythroid progenitor cells derived from ßIVS2-654-thalassaemia/HbE patients, which showed restoration of correctly spliced ß-globin mRNA and led to haemoglobin A synthesis, and consequently improved thalassaemic erythroid cell pathology. These results demonstrate proof of concept of using the engineered U7 snRNA lentiviral vector for treatment of ß-thalassaemia.


Assuntos
Processamento de RNA , RNA Nuclear Pequeno/genética , Terapêutica com RNAi/métodos , Globinas beta/genética , Talassemia beta/terapia , Animais , Células Cultivadas , Células Precursoras Eritroides/metabolismo , Vetores Genéticos/genética , Células HeLa , Hemoglobina E/genética , Hemoglobina E/metabolismo , Humanos , Camundongos , RNA Nuclear Pequeno/metabolismo , Globinas beta/metabolismo , Talassemia beta/genética
15.
Hematology ; 24(1): 459-466, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31124399

RESUMO

Background: The clinical consequences and significance of many unstable hemoglobins interacting with other hemoglobinopathies remain unrecognized. Here we first explore molecular and hematological characterizations of previously undescribed compound heterozygosity states for unstable hemoglobin Rush (Hb Rush, Beta 101 Glu > Gln, HBB:c.304G > C) with Hb E and different forms of thalassemia. Methods: Hematological assays, globin gene mutation assays and ß-globin gene cluster haplotype were conducted in 11 patients from 8 unrelated Chinese ethnic families with unexplained hemoglobin separation fraction in hemoglobin gel electrophoresis. Results: Hb Rush in various combinations with Hb E, ß0-thalassemias and α+-thalassemia were identified. Hb Rush simple heterozygote was generally associated with mild hemolytic anemia, and the compound heterozygotes of Hb Rush and the other ß-globin variants led to thalassemia intermedia phenotypes with moderate anemia. Hemoglobin electrophoreses showed that the co-presence of Hb Rush with either Hb E or ß0-thalassemias increased proportion of Hb Rush due to relative decrease of other globin chain synthesis. Beta-globin gene cluster haplotype analysis suggested a common origin of the Hb Rush variant in the Chinese families of different ethnic ancestry. Conclusions: Unstable Hb Rush interacting with ß-thalassemia result in thalassemia intermedia phenotypes, which demonstrated the clinical significance of Hb Rush and new insights into complex mechanism of clinical heterogeneity of thalassemia.


Assuntos
Hemoglobina E/genética , Hemoglobinas Anormais/genética , Talassemia beta/genética , Adolescente , Adulto , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
16.
J Clin Pathol ; 72(4): 322-324, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30630871

RESUMO

Interaction of ßE-globin gene with an in trans ß-thalassaemia gene leads to thalassaemia syndrome, known as haemoglobin (Hb) E-ß-thalassaemia disease, with variable clinical and haematological severity. Here, we reported for the first time the Hb E-ß-thalassaemia syndrome caused alternatively by an in cis interaction of ßE and a novel IVSI#7;A>G mutation, namely the Hb E-Udon Thani (HBB:c.[79G>A;92+7 A>G]). The syndrome was found in an adult Thai man (32) who was generally healthy but had an unexplained hypochromic microcytosis. Hb analysis identified heterozygous Hb E with very low Hb E expression (3.1%) and elevated Hb A2 (5.7%). Final diagnosis was made on DNA analysis, which confirmed a double mutation in a single ß-globin gene of the patient. A multiplex allele-specific PCR assay was developed for use in the screening of this novel form of Hb E-ß-thalassaemia in the population.


Assuntos
Hemoglobina E/genética , Mutação , Talassemia beta/genética , Adulto , Análise Mutacional de DNA/métodos , Predisposição Genética para Doença , Hemoglobina E/metabolismo , Heterozigoto , Humanos , Masculino , Reação em Cadeia da Polimerase Multiplex , Fenótipo , Síndrome , Talassemia beta/sangue , Talassemia beta/diagnóstico
19.
Ann Lab Med ; 39(2): 209-213, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30430785

RESUMO

Hb mutations can alter the structure, behavior, stability, or quantity of the globin chain produced. Some Hb variants shorten the erythrocyte life span, resulting in physiologically lower hemoglobin A1c (HbA1c) levels. The hemoglobin E (HbE) phenotype involves a single-nucleotide polymorphism that reduces ß-globin chain synthesis. We compared the HbA1c levels of subjects with normal Hb (HbAA; N=131) and HbE (N=148) phenotypes, examining potential hematological and biochemical factors contributing to differences in HbA1c levels. All had normal fasting plasma glucose (<5.6 mmol/L), AST, ALT, and creatinine levels. Mean±SD HbA1c levels differed between HbAA and HbE subjects: 5.5±0.3% and 5.3±0.3% (P<0.001) according to an immunoassay, and 5.5±0.3% and 5.3±0.3% (P<0.001) according to cation-exchange HPLC, respectively. In multiple logistic regression, only mean corpuscular volume (P<0.001) contributed to the difference in HbA1c levels between groups. Although a 0.2% difference in HbA1c is relatively small and unlikely to alter clinical decisions, epidemiologically, this can lead to misclassification of a significant proportion of the population, especially since the threshold of non-diabetes HbA1c (≤5.6%) falls very close to the HbA1c median of the general population.


Assuntos
Hemoglobina A Glicada/análise , Hemoglobina E/genética , Glicemia/análise , Estudos de Casos e Controles , Cromatografia Líquida de Alta Pressão , Creatinina/sangue , Estudos Transversais , Hemoglobina A/genética , Humanos , Imunoensaio , Modelos Logísticos , Fenótipo
20.
Ann Hematol ; 98(2): 289-299, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30413899

RESUMO

Thalassaemia are the most common inherited autosomal recessive single gene disorders characterized by chronic hereditary haemolytic anaemia due to the absence or reduced synthesis of one or more of the globin chains. Haemoglobin E-ß thalassaemia is the genotype responsible for approximately one half of all severe beta-thalassaemia worldwide. This study proposes to evaluate the effect of various molecular parameters on the response of hydroxyurea. Hydroxyurea was started at an initial dose of 10 mg/kg of body weight/day on 110 transfusion-dependent HbE-ß thalassaemia patients. HbF level was measured by HPLC analysis. ß-Thalassaemia mutations, XmnI and five other SNPs, and α-globin gene deletions and triplications were detected by ARMS-PCR, RFLP-PCR and Gap-PCR, respectively. Based on the factors for evaluating hydroxyurea-response, 42 patients were responders as they showed an increment of Hb from a mean baseline value of 6.45 g/dl (± 0.70) to 7.78 g/dl (± 0.72) post-therapy. Based on increase in HbF above the median value (14.72%) post-therapy, 78 patients were found to be responders. All the 78 responders showed mean decrease in transfusion of 74.26% (± 8.32) with a maximum decrease of 98.43%. There was a significant correlation between decrease in transfusion and increase in HbF level for all 78 responders. XmnI polymorphism showed the strongest association (p < 0.0001) with increase in HbF levels and Hb levels. Patients with α-globin gene deletions were better responders. It was concluded that hydroxyurea treatment is effective in transfusion-dependent HbE-ß thalassaemia patients and the response is best in patients having both XmnI polymorphism and α-deletion.


Assuntos
Transfusão de Sangue , Hemoglobina Fetal/biossíntese , Hemoglobina E/metabolismo , Hidroxiureia/administração & dosagem , Mutação , Polimorfismo de Nucleotídeo Único , Talassemia beta , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Hemoglobina Fetal/genética , Hemoglobina E/genética , Humanos , Masculino , Talassemia beta/sangue , Talassemia beta/genética , Talassemia beta/terapia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA