Molecular Analysis of β-Thalassemia Patients: First Identification of Mutations HBB:c.93-2A&gt;G and HBB:c.114G&gt;A in Brazil

Fernandes, Andréa Cristina; Shimmoto, Marily Maria Azevedo; Furuzawa, Gilberto K.; Vicari, Perla; Figueiredo, Maria Stella

doi:10.3109/03630269.2011.588354

Cited by 5 publications

(2 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Our results are in accordance with previous Brazilian studies (24)(25)(26)(27) Different from the other states in our study, the most common mutation in the state of Pernambuco was IVS-I-5 (G>C). This mutation is very common in Asia, especially in Malaysia and Indonesia and in several regions of India (29).…”

supporting

confidence: 93%

Use of an automated pyrosequencing technique for confirmation of Sickle Cell Disease

Martino

Alencar

Loureiro

et al. 2019

Preprint

View full text Add to dashboard Cite

22Background: The diagnosis of sickle cell disease (SCD) is made by hemoglobin assays such 23 as high-performance liquid chromatography (HPLC), isoelectric focusing and cellulose 24 acetate or citrate agar electrophoresis. These assays are easy to perform and used in large-25 scale newborn screening in many countries. These tests however may not easily differentiate 26 Sβ 0 thalassemia from SS or identify other hemoglobin variants, and in this case, hemoglobin 27 (HBB) gene sequencing may be necessary. Objectives: To develop a high throughput DNA 28 based confirmatory assay for SCD and to detect mutations in the HBB gene. Methods: We 29 developed an automated pyrosequencing technique (PyS) based on QIAGEN technology 30 (Hilden, Germany) to detect homozygous or heterozygous hemoglobin S mutations as well as 31 hemoglobin C mutations. The technique was tested on 2,748 samples from patients enrolled in 32 a multi-center SCD cohort in Brazil. Patients were previously tested using HPLC to diagnose 33 SCD as part of routine clinical care. Any subjects with discrepant results between HPLC and 34 PyS or with heterozygous hemoglobin S detected had Sanger sequencing of the HBB gene.35 Results: We identified 168 samples with discrepant results between HPLC and PyS and 100 36 with concordant HPLC and PyS= heterozygous S, which would suggest Sβ-thalassemia or 37 other hemoglobin S variants. The PyS assay correctly identified 1906 (98.7%) of the 1930 38 HbSS and 628 (98.7%) of the 636 HbSC samples. Of the 179 remaining samples, PyS 39 correctly indicated S heterozygosis in 165 (92.2%). Of the 165 heterozygous S samples 40 confirmed by Sanger as consistent with Sβ thalassemia genotype, 84 samples were classified 41 as Sβ 0 thalassemia and 81 as Sβ + thalassemia. The most frequent beta thalassemia mutations 42 of Sβ 0 and Sβ + were HBB: c.118C>T (Gln40Stop) and HBB c.92 + 6T> C, respectively.43Discussion: The PyS proved to be satisfactory for large-scale confirmatory testing of 44 hemoglobin mutation. Moreover, with this study we were able to describe the most common 45 3 β + and β 0 mutations in SCD patients with Sβ-thalassemia in a large multi-institutional SCD 46 cohort in Brazil. 47

show abstract

supporting

confidence: 93%

Use of an automated pyrosequencing technique for confirmation of Sickle Cell Disease

Martino

Alencar

Loureiro

et al. 2019

Preprint

View full text Add to dashboard Cite

show abstract

“…A presença da mutação IVS-I-6, a mutação β+ mais comum em nossa coorte, parece ser uma contribuição dos portugueses para a constituição genética da população, pois corresponde a 29,4% dos alelos nas mutações β + em Portugal (Bravo-Urquiola et al 54 , Rocha e Freitas 59 ). Nossos resultados estão de acordo com estudos anteriores em populações brasileiras Rocha e Freitas 59 , Fernandes et al 60 , Reichert et al 61 , Carrocini et al 62 ). Como esperado, considerando a atividade migratória da população brasileira e a ancestralidade, o padrão observado é semelhante ao das populações mediterrâneas.…”

Section: Discussionunclassified

Prevalência de beta-talassemias em pacientes com anemia falciforme em quatro estados do Brasil

Martino¹

View full text Add to dashboard Cite

RESUMOMartino CC. Prevalência de beta-talassemias em pacientes com anemia falciforme em quatro estados do Brasil [dissertação]. São Paulo: Faculdade de Medicina, Universidade de São Paulo; 2020.O diagnóstico da doença falciforme (DF) é feito por ensaios de hemoglobina (Hb), como cromatografia líquida de alta eficiência (HPLC), foco isoelétrico e eletroforese em acetato de celulose ou ágar citrato. Esses ensaios são de fácil execução e utilizados em exames de recém-nascidos em larga escala em muitos países. No entanto, esses testes podem não diferenciar facilmente a talassemia Sβ0 da SS ou identificar outras variantes da hemoglobina e, nesse caso, o sequenciamento genético do gene da beta globina (HBB) pode ser necessário. Com o objetivo de desenvolver um ensaio confirmatório com base no ácido desoxirribonucleico (DNA) de alta produtividade para DF e detectar mutações no gene HBB. Métodos: Desenvolveu-se uma técnica de pyrosequencimento automático (Pyro) de acordo com a tecnologia Qiagen (Hilden, Alemanha) para detectar mutações homozigotas ou heterozigotas da hemoglobina S (HbS), bem como mutações na hemoglobina C (HbC). A técnica foi testada em 2.748 amostras de pacientes inscritos em uma coorte multicêntrica da DF no Brasil. Os pacientes foram previamente testados usando HPLC para diagnosticar DF como parte dos cuidados clínicos de rotina. Quaisquer indivíduos com resultados discrepantes entre HPLC e Pyro ou com hemoglobina S (HbS) heterozigótica detectada realizaram sequenciamento de Sanger do gene HBB. Resultados: Foram identificadas 168 amostras com resultados discrepantes entre HPLC e Pyro e 100 com Pyro concordante = S heterozigótico e HPLC, o que sugeriria talassemia Sβ ou outras variantes S heterozigóticas. O ensaio Pyro identificou corretamente 1.906 (98,7%) das HbSS de 1.930 amostras e 628 (98,7%) das 636 amostras de Hemoglobinopatia SC (HbSC). Das 179 amostras restantes, o Pyro indicou corretamente heterozigose S em 165 (92,2%). Das 165 amostras heterozigotas de S confirmadas por Sanger como consistentes com o genótipo de talassemia Sβ, 84 amostras foram classificadas como talassemia Sβ0 e 81 como talassemia Sβ+. As mutações beta talassêmicas mais frequentes de Sβ0 e Sβ+ foram HBB:c.118C>T (Gln40Stop) e HBB:c.92+6T>C, respectivamente. Discussão: O Pyro provou ser satisfatório para testes confirmatórios em larga escala da mutação da hemoglobina. Além disso, este estudo possibilitou a descrição das mutações β+ e β0 mais comuns em pacientes com DF com Stalassemia em uma grande coorte multi-institucional de DF no Brasil.

show abstract

Mutational Profile of Homozygousβ-Thalassemia in Rio de Janeiro, Brazil

et al. 2017

View full text Add to dashboard Cite

β-Thalassemia (β-thal) is a hemolytic anemia that is caused by point mutations in most cases. The Brazilian population is highly heterogeneous and knowledge of the mutations that make up the genotypic profile of individuals can contribute information about the formation of the population and clinical condition of patients. In this study, we evaluated the mutations present in homozygous β-thal patients from Rio de Janeiro, Brazil. We analyzed 24 samples of peripheral blood of patients with homozygous β-thal. To identify the mutations, we carried out allele-specific-polymerase chain reaction (AS-PCR) and DNA sequencing. We found 11 different mutations on the β-globin gene. Among the most frequent mutations observed were HBB: c.92 + 6T>C, followed by HBB: c.93-21G>A, HBB: c.118C>T and HBB: c.92 + 1G>A. We also identified the rare mutation HBB: c.75T>A that was reported in an individual carrying Hb S (HBB: c.20A>T)/β-thal (HBB: c.75T>A) but not in Brazilian thalassemic patients, thus, this is the first report of this mutation in Brazilian β-thal patients. For its multiethnic character, Brazil has different mutations that cause β-thal and that are distributed with different frequencies according to the regions of the country. Our findings contribute to the description of the mutational profile of Brazilian thalassemic patients, showing wide heterogeneity and genetic variability.

show abstract

Molecular Analysis of β-Thalassemia Patients: First Identification of Mutations HBB:c.93-2A>G and HBB:c.114G>A in Brazil

Cited by 5 publications

References 39 publications

Use of an automated pyrosequencing technique for confirmation of Sickle Cell Disease

Use of an automated pyrosequencing technique for confirmation of Sickle Cell Disease

Prevalência de beta-talassemias em pacientes com anemia falciforme em quatro estados do Brasil

Mutational Profile of Homozygousβ-Thalassemia in Rio de Janeiro, Brazil

Contact Info

Product

Resources

About