Assuntos
Elementos Facilitadores Genéticos , Hemoglobina H/genética , alfa-Globinas/genética , Talassemia alfa/genética , Adulto , Alelos , Cromatina/genética , Cromatina/ultraestrutura , Cromossomos Humanos Par 16/genética , Cromossomos Humanos Par 16/ultraestrutura , Eritroblastos/patologia , Eritropoese , Feminino , Deleção de Genes , Regulação da Expressão Gênica , Genótipo , Hemoglobina E/genética , Hemoglobina H/análise , Humanos , Masculino , Linhagem , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Deleção de Sequência , Suriname/etnologia , alfa-Globinas/biossíntese , Talassemia alfa/sangue , Globinas beta/genéticaRESUMO
Hb E-Saskatoon [ß22(B4)GluâLys, HBB: c.67G > A] is a rare, nonpathological ß-globin variant that was first described in a Canadian woman of Scottish and Dutch ancestry and has since then been detected in several populations. The aim of the present study was to identify the origin of Hb E-Saskatoon in Brazil using ß-globin haplotypes and genetic ancestry in carriers of this hemoglobin (Hb) variant. Blood samples were investigated by isoelectric focusing (IEF) and high performance liquid chromatography (HPLC) using commercial kits. Hb E-Saskatoon was confirmed by amplification of the HBB gene, followed by sequence analysis. Haplotypes of the ß-globin gene were determined by polymerase chain reaction (PCR), followed by digestion with specific restriction enzymes. Individual ancestry was estimated with 48 biallelic insertion/deletions using three 16-plex PCR amplifications. The IEF pattern was similar to Hbs C (HBB: c.19G > A) and Hb E (HBB: c.79G > A) [isoelectric point (pI): 7.59-7.65], and HPLC results showed an elution in the Hb S (HBB: c.20A > T) window [retention time (RT): 4.26-4.38]. DNA sequencing of the amplified ß-globin gene showed a mutation at codon 22 (GAA>AAA) corresponding to Hb E-Saskatoon. A total of 11 cases of this variant were identified. In nine unrelated individuals, Hb E-Saskatoon was in linkage disequilibrium with haplotype 2 [+ - - - -]. All subjects showed a high degree of European contribution (mean = 0.85). Hb E-Saskatoon occurred on the ß-globin gene of haplotype 2 in all Brazilian carriers. These findings suggest a different genetic origin for this Hb variant from that previously described.
Assuntos
Frequência do Gene , Hemoglobina E/genética , Epidemiologia Molecular/métodos , Brasil , Variação Genética , Haplótipos , Hemoglobinopatias/genética , Hemoglobinas Anormais/genéticaAssuntos
Hemoglobina E/genética , Hemoglobina Falciforme/genética , Globinas beta/genética , Adulto , Doenças Assintomáticas , Sequência de Bases , Brasil , Pré-Escolar , Feminino , Testes Genéticos , Hemoglobina E/análise , Hemoglobina Falciforme/análise , Heterozigoto , Humanos , Lactente , Recém-Nascido , Masculino , Dados de Sequência Molecular , Triagem NeonatalRESUMO
BACKGROUND: Hemoglobinopathies are among the most studied and frequent pathologies. These genetic disorders are considered a very important health care threat in many tropical countries. Ecuador is a tropical Latin-American country with an important presence of afro-descendants (7.2%). Afro-descendants are among the ethnic groups with higher frequency of hemoglobinopathies reported. Ambuqui is a region within the Imbabura province with an important presence of afro-descendants (>50%). The present study analyzed the frequency of the most common hemoglobin variants in an asymptomatic afro-descendent population using capillary electrophoresis. FINDINGS: From 114 individuals, 25 (22%) reported a hemoglobin variant. All individuals that presented hemoglobin variants were heterozygotes (asymptomatic). Hemoglobin S (sickle cell trait) was the most frequent variant found (14%), followed by hemoglobin E (4.4%), Fetal (2.6%) and C (1%). CONCLUSION: Prevalence of hemoglobin S was consistent with populations from other countries, but it was lower than other Ecuadorian afro-descendent populations. Frequency of hemoglobin C was lower than other afro-descendent populations. This data suggests the possibility of gene flow from Native American individuals to the Ambuqui population there by lowering the frequency of their hemoglobin variants compared with other afro-descendant populations. Evaluating the frequency of hemoglobinopathies in Ecuadorian populations is essential. Despite the high frequency of these disorders, very few health care facilities implement hemoglobinopathies tests as a routine practice.
Assuntos
População Negra/genética , Hemoglobinopatias/etnologia , Hemoglobinopatias/genética , Hemoglobinas/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Equador , Eletroforese Capilar , Feminino , Hemoglobina Fetal/genética , Predisposição Genética para Doença , Genética Populacional , Hemoglobina C/genética , Hemoglobina E/genética , Hemoglobina Falciforme/genética , Heterozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Traço Falciforme/genética , Adulto JovemRESUMO
Hemoglobin profile studies have been carried out in four samples from different districts of Porto Velho (Rondônia State) in the western Amazonian region of Brazil: Candelária, Bate Estaca, Hemeron (at the State Blood Bank), and São Carlos. Samples from 337 unrelated individuals were collected during medical and paramedical team visits by professionals from the Instituto de Pesquisa em Patologia Tropical and the Centro de Pesquisa em Patologias Tropicais (both research institutes in tropical diseases). The aim of this study is to assess the frequency of alleles in the hemoglobin system, mainly alleles HB*A, *S, and *E. The overall phenotype frequencies were HB A,S = 0.025, HB A,E = 0.006, and HB A,A = 0.969. Samples from the blood bank subjects and samples from the homogeneous areas of São Carlos and Candelária plus Bate Estaca have a chi-square of heterogeneity of 6.383 (p = 0.041) and 8.406 (p = 0.015), respectively. The allele frequencies (HB*A = 0.984, HB*S = 0.012, and HB*E = 0.003) do not significantly differ from frequencies found in other Brazilian regions.
Assuntos
Frequência do Gene , Genética Populacional/estatística & dados numéricos , Hemoglobina A/genética , Hemoglobina E/genética , Hemoglobina Falciforme/genética , Polimorfismo Genético/genética , Animais , População Negra/genética , Brasil , Emigração e Imigração , Fluxo Gênico/genética , Deriva Genética , Humanos , Indígenas Sul-Americanos/genética , Funções Verossimilhança , Malária/sangue , Malária/genética , Malária/prevenção & controle , Fenótipo , Plasmodium/genética , População Branca/genéticaRESUMO
Two unrelated individuals previously diagnosed as hemoglobin (Hb) EE were found to be, in fact, Hb EE with Hb H disease. This globin genotype normally results as Hb EF Bart disease. This unusual genotype-phenotype interaction highlights the need for molecular analysis in affected individuals with Hb E disorders before appropriate genetic counseling and genetic risk estimation in offspring can be given.
Assuntos
Hemoglobina E , Talassemia alfa/genética , Talassemia beta/genética , Adulto , Criança , Feminino , Globinas/genética , Homozigoto , Humanos , Lactente , Masculino , Linhagem , Fenótipo , Tailândia , Talassemia alfa/diagnósticoRESUMO
Se realizó un estudio de tipo descriptivo y transversal donde se evaluaron 38 pacientes con diagnóstico de infarto de miocardio (IM) o angina inestable, basado en los criterios clínicos, electrocardiográficos y enzimáticos preestablecidos que ingresaron a la unidad de cuidados coronarios del Hospital Dr. Domingo Luciani desde julio hasta septiembre de 1992, descartándose en todos ellos a través del interrogatorio enfermedades alérgicas, asma bronquial, transfunsiones sanguíneas recientes, uso de glucocorticoides, presencia de mieloma IgE o un síndrome de hiper IgE; A través de un frotis de sangre periférica la presencia de eosinofília y mediante examen de heces especial la presencia de parasitosis intestinal. A todos los pacientes se les hizo una determinación de colesterol y triglicéridos a la semana del evento isquémico y de IgE sérica durante los días 1, 3, 8, 15 y 21 desde el ingreso del paciente, tomándose la primera muestra en un tiempo promedio de 11 horas, demostrándose una evidente asociación entre valores elevados IgE séricas y cardiopatía isquémica del tipo IM o angina inestable. Los valores séricos de IgE en nuestros pacientes isquémicos fueron superiores a los descritos en poblaciones normales tanto de estudios internacionales como de nuestro país; además, se demostró una diferencia estadísticamente significativa entre valores IgE sérica del grupo de paciente con IM y el grupo de pacientes con angina inestable estando más elevada en los primeros. En presencia de hábitos tabaquicos y edad superior a los 53 años, la tendencia a presentar niveles elevados de IgE sérica aumenta. De manera que niveles elevados de IgE, al igual que el tabaquismo y la edad pudieran representar un factor de riesgo adicional para cardiopatía isquémica
Assuntos
Humanos , Masculino , Feminino , Angina Instável , Hemoglobina E , Infarto do Miocárdio , Isquemia Miocárdica , VenezuelaRESUMO
Hemoglobin E (HbE), alpha-thalassemia, and beta-thalassemia are common among Southeast Asians and often occur in compound heterozygous states that complicate neonatal screening. We describe a kindred with alpha-thalassemia-1, HbE, and beta zero-thalassemia. The proband had HbE/beta zero-thalassemia, with severe anemia and failure to thrive. His father also had HbE/beta zero-thalassemia but had coinherited alpha-thalassemia-1 and was free of symptoms.