Hemoglobina Denver, una causa de desaturación en oximetría de pulso. Reporte de caso en un paciente pediátrico / Hemoglobin Denver, a cause of desaturated pulse oximetry. A pediatric case report

Las hemoglobinopatías son trastornos genéticos que afectan a la molécula de hemoglobina (Hb). Las mutaciones en las cadenas a o b que alteran el tetrámero de Hb pueden modificar la capacidad de la molécula para unirse al oxígeno. Las hemoglobinopatías con baja afinidad al oxígeno pueden presentarse con cianosis y una lectura alterada de la oximetría de pulso, lo que lleva a pruebas innecesarias y, a veces, invasivas para descartar afecciones cardiovasculares y respiratorias. En el siguiente reporte de caso, presentamos a una paciente pediátrica, asintomática, que se presentó a la consulta por detección de desaturación en oximetría de pulso. Las pruebas de laboratorio iniciales mostraron una anemia normocítica, normocrómica. Las muestras de gas venoso demostraron una p50 elevada. Después de extensas herramientas de diagnóstico, se diagnosticó una variante de Hb con baja afinidad al oxígeno, Hb Denver.

Hemoglobinopathies are genetic disorders that affect the hemoglobin (Hb) molecule. Mutations in the alpha or beta chains altering the Hb tetramer may modify the molecule's oxygen-binding capacity. Hemoglobinopathies with low oxygen affinity may occur with cyanosis and an altered pulse oximetry reading, leading to unnecessary and sometimes invasive tests to rule out cardiovascular and respiratory conditions. In the case report described here, we present an asymptomatic pediatric patient who consulted for desaturated pulse oximetry. Her initial laboratory tests showed normocytic, normochromic anemia. Venous blood gas samples showed an elevated p50. After using extensive diagnostic tools, a variant of Hb with low oxygen affinity was diagnosed: Hb Denver.

Epidemiological Survey of Hemoglobinopathies Based on Next-Generation Sequencing Platform in Hunan Province, China / 生物医学与环境科学（英文）

OBJECTIVE@#This study was aimed at investigating the carrier rate of, and molecular variation in, α- and β-globin gene mutations in Hunan Province.@*METHODS@#We recruited 25,946 individuals attending premarital screening from 42 districts and counties in all 14 cities of Hunan Province. Hematological screening was performed, and molecular parameters were assessed.@*RESULTS@#The overall carrier rate of thalassemia was 7.1%, including 4.83% for α-thalassemia, 2.15% for β-thalassemia, and 0.12% for both α- and β-thalassemia. The highest carrier rate of thalassemia was in Yongzhou (14.57%). The most abundant genotype of α-thalassemia and β-thalassemia was -α 3.7/αα (50.23%) and β IVS-II-654/β N (28.23%), respectively. Four α-globin mutations [CD108 (ACC>AAC), CAP +29 (G>C), Hb Agrinio and Hb Cervantes] and six β-globin mutations [CAP +8 (C>T), IVS-II-848 (C>T), -56 (G>C), beta nt-77 (G>C), codon 20/21 (-TGGA) and Hb Knossos] had not previously been identified in China. Furthermore, this study provides the first report of the carrier rates of abnormal hemoglobin variants and α-globin triplication in Hunan Province, which were 0.49% and 1.99%, respectively.@*CONCLUSION@#Our study demonstrates the high complexity and diversity of thalassemia gene mutations in the Hunan population. The results should facilitate genetic counselling and the prevention of severe thalassemia in this region.

Occurrence of unusual haemoglobinopathies in balochistan: hb sd and hb se - presentation with osteomyelitis / Ocorrência de hemoglobinopatias incomuns no baluchistão: hb sd e hb se - apresentação com osteomielite

ABSTRACT Objective: To describe two cases of unusual variants of sickle cell disease. Case description: We present two cases of sickle cell disease variants (haemoglobinopathies), from unrelated families, in the state of Balochistan (Pakistan). One was diagnosed with sickle cell disease in the haemoglobin electrophoresis, whereas the other was diagnosed with sickle cell SE disease. Both were diagnosed based on the presentation of osteomyelitis. Comments: Haemoglobin SD disease (Hb SD) and haemoglobin SE disease (Hb SE) are rare haemoglobinopathies in the world. The lack of available literature suggests that both are variants of sickle cell disease (SCD), with heterogeneous nature. The prevalence of sickle cell disease with compound heterozygotes was found at a variable frequency in the population of the Asian Southeast. The frequency of osteomyelitis in SCD is 12 to 18%, but its occurrence among variant haemoglobinopathies is little reported. Both reported cases presented with osteomyelitis as a characteristic of the disease presentation.

RESUMO Objetivo: Descrever dois casos de variantes raras da hemoglobinopatia falciforme. Descrição do caso: Apresentamos aqui dois casos de hemoglobinopatias variantes das células falciformes, de famílias não relacionadas, no estado do Baluchistão (Paquistão), sendo um diagnosticado como doença da hemoglobina SD na eletroforese de hemoglobina, enquanto o outro com doença da hemoglobina SE. Ambos foram diagnosticados a partir da apresentação de osteomielite. Comentários: Hemoglobina SD (Hb SD) e hemoglobina SE (Hb SE) são hemoglobinopatias raras no mundo. A escassez de literatura disponível sugere que ambas são variantes da doença falciforme (DF) com natureza heterogênea. A prevalência de hemoglobinopatia falciforme com heterozigosidade composta foi encontrada com frequência variável na população do sudeste asiático. A frequência de osteomielite na DF é de 12 a 18%, mas sua ocorrência entre as hemoglobinopatias falciformes variantes é pouco relatada. Os dois casos reportados apresentaram osteomielite como característica de apresentação da doença.

Anemias hemolíticas hereditarias por defectos en la síntesis de globina / Hereditary hemolytic anemias due to defective globin synthesis

Introducción: Los defectos genéticos en la molécula de hemoglobina se dividen en aquellos que tienen una tasa reducida de producción de una o más cadenas de globina, las talasemias; y en los que se producen cambios estructurales que conducen a inestabilidad o transporte anormal de oxígeno. Objetivo: Explicar los diferentes mecanismos por los cuales ocurren las talasemias y otras alteraciones en la síntesis de las cadenas de globina, así como las características moleculares, fisiopatogénicas y los cambios hematológicos. Métodos: Se realizó una revisión de la literatura, en inglés y español, a través del sitio web PubMed y el motor de búsqueda Google académico de artículos publicados en los últimos 10 años. Se hizo un análisis y resumen de la bibliografía revisada. Análisis y síntesis de la información: Las talasemias son un grupo heterogéneo de defectos genéticos en la síntesis de hemoglobina, que causa una disminución en la tasa de producción de una o más cadenas de la molécula. De acuerdo a la cadena de globina que presenta el defecto se dividen en α-β-, δβ- o γδβ-talasemias. Conclusiones: Las talasemias y las hemoglobinopatías son las enfermedades hemolíticas hereditarias más comunes en muchas partes del mundo, caracterizadas por complejas interacciones entre anemia, eritropoyesis ineficaz y alteraciones del metabolismo del hierro(AU)

Introduction: Genetic disorders in the hemoglobin molecule are divided into those that have a reduced rate of production of one or more globin chains, thalassemias; and those in which structural changes occur that lead to instability or abnormal oxygen transport. Objective: To explain the different mechanisms by which thalassemias and other alterations in the synthesis of globin chains occur, as well as molecular, physiopathogenic and hematological changes. Methods: A review of the literature in English and Spanish was carried out through the PubMed website and the Google Scholar search engine, searching for articles published in the last ten years. The revised bibliography was analyzed and summarized. Information analysis and synthesis: Thalassemias make up a heterogeneous group of genetic defects in the synthesis of hemoglobin, which causes a decrease in the rate of production of one or more chains of the molecule. According to the globin chain that presents the defect, they are divided into α-β-, δβ- or γδβ-thalassemias. Conclusions: Thalassemias and hemoglobinopathies are the most common hereditary hemolytic diseases in many parts of the world. They are characterized by complex interactions between anemia, ineffective erythropoiesis, and alterations in iron metabolism(AU)

Enfermedad por hemoglobina H: primer caso de dobles heterocigotos hemoglobina Constant Spring / Sudeste Asiático en Costa Rica / Hemoglobin H disease: first case of double heterozygous hemoglobin Constant Spring / Southeast Asian in Costa Rica

Resumen La enfermedad por hemoglobina H es un cuadro clínico que se presenta en las alfa talasemias, las cuales son enfermedades que cursan con anemia microcítica hipocrómica, debidas principalmente a deleciones en el gen de alfaglobina, lo que disminuye la producción de la cadena de alfa globina y promueve la formación de variantes de hemoglobina. Cuando se detectan variantes de hemoglobina en las alfa talasemias, por lo general, se debe a genotipos homocigotas o dobles heterocigotas para mutaciones y deleciones del gen de alfa globina coheredadas. En este artículo se describe el primer caso en Costa Rica, de dos hermanos con enfermedad por hemoglobina H, que fenotípicamente presentaron las variantes de hemoglobina H y hemoglobina Constant Spring en el análisis electroforético de la hemoglobina, y cuyo análisis molecular del gen de alfa globina detectó tanto la deleción sudeste asiático como la mutación para hemoglobina Constant Spring, siendo diagnosticados como dobles heterocigotos por alfa talasemia (genotipo --SEA/ααCS).

Abstract Hemoglobin H disease occurs in patients with alpha thalassemia, diseases associated with hypochromic microcytic anemia, mainly due to deletions in the alpha globin gene, which decreases the production of the alpha globin chain and promotes the formation of hemoglobin variants. When hemoglobin variants are detected in alpha thalassemias it is usually due to homozygoys or doublé heterozygous genotypes, for mutations and deletions of the alpha globin gene. This article describes the first case in Costa Rica of two siblings with hemoglobin H disease, who phenotypically presented the hemoglobin H and Constant Spring hemoglobin variants in the electrophoretic analysis of the hemoglobin, and whose molecular DNA analysis of the alpha globin gene detected both, the Southeast Asian deletion and the mutation for Constant Spring Hemoglobin, being diagnosed as compound heterozygous for alpha thalassemia (genotipe --SEA/ααCS).

Regulación de expresión de genes de la familia de ß-globina humana, útil en la búsqueda de nuevos blancos terapéuticos para tratamiento de hemoglobinopatías / Regulation of the ß-globin gene family expression, useful in the search for new therapeutic targets for hemoglobinopathies

Durante la etapa embrionaria, el desarrollo fetal y la vida posnatal se expresan isoformas funcionalmente distintas de hemoglobina, producto de la combinación de cadenas polipeptídicas sintetizadas a partir de los distintos genes que componen las familias de α- y β-globina. En función de que la presencia de altos niveles de hemoglobina fetal (Hb F) es beneficiosa en síndromes falciformes y talasémicos graves, se plantea revisar las bases de la regulación de la expresión de los genes de la familia de β-globina, en particular los genes que codifican las cadenas de γ-globina (HBG1 y HBG2). En este trabajo se revisan los conocimientos sobre factores de transcripción y reguladores epigenéticos que gobiernan los eventos de encendido y apagado de los genes de la familia de β-globina. Se espera que la consolidación de estos conocimientos permita hallar nuevos blancos terapéuticos para el tratamiento de hemoglobinopatías.

Different hemoglobin isoforms are expressed during the embryonic, fetal and postnatal stages. They are formed by combination of polypeptide chains synthesized from the α- and β- globin gene clusters. Based on the fact that the presence of high hemoglobin F levels is beneficial in both sickle cell disease and severe thalassemic syndromes, a revision of the regulation of the β-globin cluster expression is proposed, especially regarding the genes encoding the γ-globin chains (HBG1 and HBG2). In this review we describe the current knowledge about transcription factors and epigenetic regulators involved in the switches of the β-globin cluster. It is expected that the consolidation of knowledge in this field will allow finding new therapeutic targets for the treatment of hemoglobinopathies.

Genetic counseling for individuals with hemoglobin disorders and for their relatives: a systematic literature review / Asesoramiento genético para individuos con alteraciones de las hemoglobinas y sus familiares: revisión sistemática de literatura / Aconselhamento genético para indivíduos com alterações das hemoglobinas e seus familiares: revisão sistemática de literatura

Objective: To identify genetic counseling programs that do not encourage therapeutic abortion for individuals with hemoglobin disorders and/or for their relatives. Method: Systematic literature review of articles published from 2001 to 2012 that are located in the PubMed, LILACS, SciELO and SCOPUS databases using keywords in Portuguese, English and Spanish and that met the inclusion and exclusion criteria described on a standardized form. Results: A total of 409 articles were located, but only eight (1.9%) were selected for analysis. Conclusion: Although seldom mentioned in the literature, educational/preventive programs targeting hemoglobinopathies are feasible and allow the affected individuals to acquire knowledge on the consequences of this condition and their odds of transmitting it.

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Objetivo: Identificar programas de asesoramiento genético sin incentivo al aborto terapéutico para individuos con alteraciones de las hemoglobinas y/o sus familiares. Método: Revisión sistemática de literatura realizada en las bases de datos PubMed, LILACS, SciELO y SCOPUS por artículos publicados de 2001 a 2012, utilizando descriptores en portugués, inglés y español, según formularios estandarizados que abarcaban criterios de inclusión y exclusión. Resultados: De los 409 estudios encontrados solo ocho (1,9%) fueron seleccionados. Conclusión: Los programas de educación/prevención para hemoglobinopatías, aunque rara vez encontrados en la literatura, son posibles y permiten que los individuos adquieran conocimiento acerca de las consecuencias de su disturbio y la probabilidad de trasmitirlo.

Objetivo Identificar programas de aconselhamento genético sem incentivo ao aborto terapêutico para indivíduos com alterações das hemoglobinas e/ou seus familiares. Método Revisão sistemática de literatura realizada nas bases de dados PubMed, LILACS, SciELO e SCOPUS por artigos publicados de 2001 a 2012, utilizando descritores em português, inglês e espanhol, de acordo com formulários padronizados contendo critérios de inclusão e exclusão. Resultados Dos 409 estudos encontrados somente oito (1,9%) foram selecionados. Conclusão Os programas de educação/prevenção para hemoglobinopatias, embora raramente encontrados na literatura, são possíveis e permitem que indivíduos adquiram conhecimento sobre as consequências de seu distúrbio e a probabilidade de transmití-lo.
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Double heterozygous hemoglobin Q India/hemoglobin D Punjab hemoglobinopathy: Report of two rare cases.

Cation exchange high performance liquid chromatography (CE HPLC) provides an excellent tool for accurate and reliable diagnosis of various hemoglobin (Hb) disorders. HbQ India is a rare alpha chain variant that usually presents in the heterozygous state. Its presence in double heterozygous state with HbD Punjab is extremely rare. The double heterozygosity for a and b chain variants leads to formation of abnormal heterodimer hybrids, which can lead to diagnostic dilemmas. We report two rare cases of double heterozygous HbQ India/HbD Punjab where the hybrid Hb was seen to elute at retention time similar to HbC on CE HPLC. The first case had unconjugated hyperbilirubinemia at presentation; while, the second case was asymptomatic.

Hemoglobin E disorder: Newborn screening program.

Hemoglobin E (Hb E) disorder is an important kind of hemoglobinopathy. It can be seen around the world with the highest prevalence in Southeast Asia. The screening for this disorder becomes the public health policies in many countries. The screening can be performed in several population groups. The newborn screening program for Hb E disorder is an important issue in pediatric genetics. In this brief review, the author discusses on important laboratory tests for screening for Hb E disorder in newborn.

Molecular characterization of hemoglobin D Punjab traits and clinical-hematological profile of the patients / Caracterização molecular dos traços de hemoglobina D Punjab e perfil clínico-hematológico dos pacientes

CONTEXT AND OBJECTIVE: Hemoglobin (Hb) D hemoglobinopathies are widespread diseases in northwestern India and usually present with mild hemolytic anemia and mild to moderate splenomegaly. The heterozygous form of Hb D is clinically silent, but coinheritance of Hb D with Hb S or beta-thalassemia produces clinically significant conditions like thalassemia intermedia of moderate severity. Under heterozygous conditions with coinheritance of alpha and beta-thalassemia, patients show a degree of clinical variability. Thus, our aim was to molecularly characterize the Hb D trait among individuals who were clinically symptomatic because of co-inheritance of alpha deletions or any beta-globin gene mutations. DESIGN AND SETTING: This was a cross-sectional study conducted in an autonomous tertiary-care hospital. METHODS: Complete blood count and red cell indices were measured using an automated cell analyzer. Quantitative assessment of hemoglobin Hb F, Hb A, Hb A2 and Hb D was performed by means of high performance liquid chromatography (HPLC). DNA extraction was done using the phenol-chloroform method. Molecular analyses on common alpha deletions and common beta mutations were done using the Gap polymerase chain reaction and Amplification Refractory Mutation System, respectively. RESULTS: We evaluated 30 patients and found clinical variation in the behavior of Hb D traits. In six patients, the Hb D traits were clinically symptomatic and behaved like those of thalassemia intermedia. Molecular characterization showed that three out of these six were IVS-1-5 positive. CONCLUSIONS: HPLC may not be the gold standard for diagnosing symptomatic Hb D Punjab traits. Hence, standard confirmation should include molecular studies.

CONTEXTO E OBJETIVO: Hemoglobinopatias da hemoglobina (Hb) D são doenças amplamente disseminadas no noroeste da Índia e geralmente se apresentam com anemia hemolítica leve e esplenomegalia leve a moderada. A forma heterozigótica de Hb D é clinicamente silenciosa, mas co-herança de Hb D com Hb S ou beta-talassemia produzem condições clinicamente significativas, como talassemia intermediária de gravidade moderada. Em condição heterozigótica com co-herança de alfa e beta-talassemia, pacientes mostram variabilidade clínica. Assim, nosso objetivo foi a caracterização molecular dos traços da Hb D em individuos clinicamente sintomáticos, devido à co-herança de deleções de alfa ou quaisquer mutações gênicas de beta-globina. TIPO DE ESTUDO E LOCAL: Estudo transversal; realizado em um hospital de cuidado terciário autônomo. MÉTODOS: Hemograma completo e índices de células vermelhas foram medidos pelo analisador automatizado de células. Avaliação quantitativa de hemoglobina Hb F, Hb A, Hb A2 e Hb D foi realizada por cromatografia líquida de alta eficiência. Extração de DNA foi feita pelo método de fenol-clorofórmio. Estudo molecular para deleções comuns de alfa e mutações comuns de beta foi feito por Gap-reação em cadeia da polimerase e amplificação refratária de mutação, respectivamente. RESULTADOS: Avaliamos 30 pacientes e verificamos variação clínica no comportamento dos traços da Hb D. Em seis pacientes, os traços da Hb D foram clinicamente sintomáticos e se comportavam como os de talassemia intermédia. A caracterização molecular mostrou que três desses seis pacientes eram IVS-1-5 positivos. CONCLUSÕES: HPLC pode não ser o padrão ouro para o diagnóstico de traços de Hb D Punjab sintomáticos. Assim, a confirmação padrão ouro deve incluir estudos moleculares.

Ethical issues in genetic counselling with special reference to haemoglobinopathies.

Genetic counselling is provided in places where genetic tests are carried out. The process involves pre-test counselling as well as post-test counselling to enable the individuals to face the situation and take appropriate decisions with the right frame of mind. Major ethical principles which govern the attitudes and actions of counsellors include: respect for patient autonomy, non-maleficence, beneficence, or taking action to help benefit others and prevent harm, both physical and mental, and justice, which requires that services be distributed fairly to those in need. Other moral issues include veracity, the duty to disclose information or to be truthful, and respect for patient confidentiality. Nondirective counselling, a hallmark of this profession, is in accordance with the principle of individual autonomy. High prevalence of haemoglobinopathies with availability of good and sensitive carrier detection tests and prenatal diagnostic techniques makes these good candidates for population screening of carriers along with genetic counselling for primary prevention of the disease. Screening of the extended family members of the affected child, high risk communities and general population screening including antenatal women are the main target groups for planning a Haemoglobinopathy control programme. A critical mass of trained genetic counsellors who have understanding of the ethical issues and its appropriate handling with the required sensitivity is needed in India.

Frequency of β-thalassemia trait and other hemoglobinopathies in northern and western India.

INTRODUCTION: India is an ethnically diverse country with an approximate population of 1.2 billion. The frequency of beta-thalassemia trait (βTT) has variously been reported from <1% to 17% and an average of 3.3%. Most of these studies have been carried out on small population groups and some have been based on hospital-based patients. There is also a variation in the prevalence of hemoglobinopathies in different regions and population groups in the country. A high frequency of Hb D has been reported from the North in the Punjabi population, Hb E in the eastern region of India and Hb S is mainly reported from populations of tribal origin from different parts of the country. OBJECTIVES: To study the gene frequency of βTT and other hemoglobinopathies in three regions East (Kolkata), West (Mumbai) and North (Delhi) in larghe population group (schoolchildren) for a more accurate assessment of gene frequency for planning of control programmes for haemoglobinopathies. MATERIALS AND METHODS: This study included 5408 children from 11 schools in Delhi, 5682 from 75 schools in Mumbai and 957 schoolchildren from Kolkata who were screened for βTT and haemoglobinopathies. These included 5684 children from 75 schools in Mumbai and 5408 children from 11 schools in Delhi. Children were 11-18 years of age of both sexes. The final report is, however, only on 11090 schoolchildren from Mumbai and Delhi as data from Kolkata was restricted both in numbers and objectives and could not be included for comparison. RESULTS: The overall gene frequency of βTT in Mumbai and Delhi was 4.05% being 2.68% and 5.47% in children of the two cities respectively. In Mumbai, the gene frequency was evenly distributed. Majority of the children with βTT from Mumbai were from Marathi (38.9%) and Gujarati (25%) speaking groups. Gene frequency was >5% in Bhatias, Khatris, Lohanas and Schedule Castes. In Delhi, a higher incidence was observed in schoolchildren of North and West Delhi (5.8-9.2%). The schoolchildren of North and West Delhi comprised predominantly of Punjabi origin compared to children in the South of the city (2.2%, 2.3%). When analyzed state-wise, the highest incidence was observed in children of Punjabi origin (7.6%) and was >4% from several other states. Majority of the traits from Mumbai were anemic (95.1% male and 85.6% in female). The prevalence of anemia was lower (62.7% male and 58.4% female) children with βTT from Delhi. This was a reflection of the higher prevalence of anemia in children without hemoglobinopathy in Mumbai than in Delhi. Nutritional deficiency was probably more severe and rampant in children Mumbai. Gene frequency of Hb D was greater in schoolchildren from Delhi (1.1%) than in Mumbai (0.7%). Hb S trait (0.2%) was observed exclusively in children from Mumbai. A low incidence of Hb E trait (0.04%) was seen in children in Mumbai. A higher incidence is reported from the East. The number of cases studied from the eastern region was small as the data from the East (Kolkata) could not be included in the analysis. CONCLUSION: This study comprises a larger number of children studied for the gene frequency of βTT and other hemoglobinopathies from India. Population groups with higher gene frequencies require screening programmes and facilities for antenatal diagnosis as well as increased awareness and educational programmes to control the birth of thalassemic homozygotes. The overall carrier frequency of βTT was 4.05% and reinforces the differential frequency of β-thalassemia trait in schoolchildren from Delhi and Mumbai and the higher incidence of hemoglobin D in Punjabis as reported previously. The birth incidence calculated thereof for homozygous thalassemics would be 11,316 per year which are added each year to the existing load of homozygous thalassemics. This is much higher than the previously reported number of births annually. Hence suitable control measures need to be undertaken urgently in India.

Utility of family studies in diagnosing abnormal hemoglobins/thalassemic states.

Objective. To resolve all indeterminate cases on HPLC screening with the help of family studies and to further confirm the results by genetic analysis. Methods. In our 11 years experience with HPLC at Sir Ganga Ram Hospital, we solved many cases with the help of family studies on parental blood samples in which patient could have possibly been homozygous vs compound heterozygous. Genetic analysis was done on index case as well as on parental samples with ARMS-PCR technique to confirm the results. Results. In 100% of cases, we noted that the diagnosis obtained by family studies was commensurate with that obtained by DNA analysis. Conclusion. In centers, which do not have the facility for genetic analysis, family studies by HPLC can be equally useful.

Advances in management of thalassemia.

Thalassemias represent the most common single-gene disorder causing a major public health problem in India. Thalassemia and hemoglobinopathies probably developed over 7000 years ago as a defense against malaria. In simple terms, thalassemia is caused by a mutation in either the â-globin chain or the á-globin chain which combine equally in red cells to form hemoglobin. These mutations lead to varying degree of anemia resulting into thalassemia minor, intermedia or major. Present write up relates to advances in the management of â-thalassemia major.

Ocorrência de hemoglobina S no estado de Mato Grosso do Sul, Brasil / Occurrence of hemoglobin S in Mato Grosso do Sul state, Brazil

INTRODUÇÃO: As hemoglobinopatias são as alterações genéticas mais comuns no homem, sendo a hemoglobina (Hb) S a mais freqüente entre todas. Sua ocorrência no estado de Mato Grosso do Sul ainda não foi sistematicamente avaliada. OBJETIVOS: Caracterizar a ocorrência de Hb S por genótipos, sexo, idade no momento do diagnóstico, índice de cobertura e prevalência em Mato Grosso do Sul. MATERIAL E MÉTODO: Estudo retrospectivo, transversal e descritivo, desenvolvido com os resultados de triagem neonatal para hemoglobinopatias, utilizando a técnica de cromatografia líquida de alta pressão, no Instituto de Pesquisas, Ensino e Diagnósticos da Associação de Pais e Amigos dos Excepcionais (IPED/APAE) de Mato Grosso do Sul em 2000-2005. RESULTADOS: De 190.809 indivíduos triados, 2.624 (1,38 por cento) encontraram-se alterados, correspondendo a 2.385 neonatos e 239 crianças maiores de 28 dias. Não houve diferença entre os sexos, sendo 1.335 do sexo feminino e 1.289 do masculino. Os genótipos alterados encontrados foram traço falciforme (FAS [99,16 por cento]) e doenças falciformes (FS [0,61 por cento] e FSC [0,23 por cento]). CONCLUSÃO: Esse primeiro estudo de triagem realizado no estado de Mato Grosso do Sul mostra que o programa desenvolvido pelo IPED/APAE está se solidificando no estado e avançando em relação ao índice de cobertura da população e ao diagnóstico precoce. Esses indicadores podem embasar ações preventivas (aconselhamento genético e estudos familiares) e assistenciais (tratamento ambulatorial contínuo), que visam à redução da morbimortalidade de indivíduos acometidos por essas afecções no estado.

BACKGROUND: Hemoglobinopathies are the most common genetic disorders in humans and Hb S is the most frequent among them. Its occurrence in the state of Mato Grosso do Sul has not been systematically analyzed yet. OBJECTIVES: To describe the occurrence of hemoglobin S according to genotypes, gender, age at the moment of diagnosis, cover index and prevalence in the state of Mato Grosso do Sul. MATERIAL AND METHOD: Retrospective, transversal and descriptive study of the results of neonatal screening for hemoglobinopathies performed with high pressure liquid chromatography technique at Instituto de Pesquisa, Ensino e Diagnósticos da Associação dos Pais e Amigos dos Excepcionais (IPED/APAE) in the state of Mato Grosso do Sul (2000-2005). RESULTS: Among 190,809 screened individuals, 2,624 (1.38 percent) showed alterations, 2,385 were neonates and 239 were children aged 28 days or more. There was no difference in gender (1,335 females and 1,289 males). The altered genotypes were FAS (99.16 percent), FS (0.61 percent) and FSC (0.23 percent). CONCLUSION: This first study of neonatal screening in the state of Mato Grosso do Sul revealed that the state program developed by IPED/APAE has been consolidating and advancing as to cover index and early diagnosis. These indicators may be the basis for preventive (genetic counseling and family studies) and assistance measures (continuous ambulatory treatment), which aim at the reduction of morbimortality in individuals with these hemoglobinopathies in the state.

Contribution to the study of molecular defects of hemoglobin in the Brazilian population

The hemoglobinopathies belong to a diverse group of inherited disorders characterized by the reduced synthesis of one or more globin chains (thalassemia) or the synthesisof a structurally abnormal hemoglobin (Hb). Approximately 900 different hemoglobin variants characterized by mutations involving alpha, beta, gamma, and delta globin chains have been described worldwide. In Brazil, the high degree of ethnic admixture among native Americans and African and European descendants has produced elevated frequencies of Hb alterations. The aim of the present study was to characterize globin chain mutants based on classical laboratory tests and molecular analyses to supply detailed informationabout the Hb diseases to health professionals and to contribute to the knowledge of abnormal hemoglobins in Brazil. A total of 242 samples were submitted to classical tests selected for hemoglobinopathies, and molecular screening was carried out by PCR-based techniques that included allele-specific PCR, multiplex PCR, restriction enzyme analysis PCR, and direct sequencing. After conducting the classical tests, the samples were divided into five groups in accordance with the mutant chain. The groups with alpha and beta globin chain mutants were the most frequent, with 81 samples each. Another group with a large number of samples was that of unidentified mutants, with 56 samples. The delta and fusing delta/beta globin chain groups had fewer numbers of samples, respectively, 13 and 11. The most frequent electrophoretic profile was the Hb S-like, followed by fast variants. Some sample of the beta globin chain group could only be identified after sequencing, such as the samples Hb D-Los Angeles, Hb Korle-Bu, Hb K-Woolwich, Hb E, Hb Deer Lodge, Hb Osu-Christiansborg, and Hb Ohio. It was possible to detect a previously undescribed variant in four individuals of this sampling, who were not related and from different locations. For the alpha globin chain mutants, sequencing of the...

Diagnóstico de hemaglobinopatia A/Korle-Bu em uma família na cidade de São Paulo / A/Korle-Bu haemoglobinopathy diagnosis in a family in São Paulo city

Objetivo: descrever uma família da cidade de São Paulo, portadora de heterozigose para uma variante rara de hemoglobina e enfatizar o diagnóstico diferencial entre as hemoglobinas S, D e Korle-Bu...

Objective: to describe the case of a family from São Paulo, SP whose members had been heterozygote for a rare hemoglobin subset, and remarking of hemoglobin S, D and Korle-Bu disease differential diagnosis...

Hemoglobinopatías en Venezuela: incidencia, orígen y caracterización molecular / Hemoglobinopathies in Venezuela: incidence, origin and molecular characterization

Con el presente estudio se pretendió implementar las bases metodológicas para la caracterización de las hemoglobinopatías con interés en el área clínica, antropológica y genética. Los resultados y las técnicas estandarizadas en nuestro laboratorio están a la disposición de la comunidad científica nacional y de las instituciones dispensadoras de salud y pueden extenderse también a los países de lberoamérica que lo requieran. Se estudiaron 80.400 muestras provenientes de estudios poblacionales en diferentes regiones del país y de pacientes atendidos en los Laboratorios de Hemoglobinas Anormales del HUC y de Hematología Experimental del IVIC. A cada individuo se le extrajo 10 ml de sangre periférica en un tubo con EDTA. Un grupo fue estudiado por electroforesis de hemoglobina en acetato de celulosa y en citrato agar, prueba de solubilidad, cuantificación de Hb A2 por microcromatografía en columna y cuantificación de Hb F por desnaturalización por álcali y otro por HPLC-CE, PCR, Reverse Dot Blot, ARMS - PCR, DGGE, RFLP, GAP - PCR y Secuenciación Automatizada. Se concluyó que en Venezuela la distribución de las hemoglobinopatías es heterogénea, el método de HPLC-CE es rápido, sensible y preciso, la drepanocitosis es una enfermedad multicromosomal, la deleción ?-³¯ -3.7 talasemia es la más frecuente en nuestro país, se evidenció que la mezcla racial en los Warao ocurrió en los últimos treinta años, las hemoglobinopatías representan un problema de salud pública y que la detección o pesquisa neonatal debe ser obligatoria.

The Agamma-195 (C->G) mutation in hereditary persistence of fetal hemoglobin is not associated with activation of a reporter gene in vitro

Hereditary persistence of fetal hemoglobin is an uncommon, benign disorder in which the expression of gamma-globin genes persists into adult life. Several point mutations have been associated with the increased gamma-globin gene promoter activity. We evaluated the -195 (C->G) mutation by a functional in vitro assay based on the luciferase reporter gene system. The results indicated that the increased promoter activity observed in vivo could not be reproduced in vitro under the conditions employed, suggesting that other factors may be involved in the overexpression of the gamma-globin gene containing the -195 (C->G) mutation. Furthermore, this is the first time that the -195 (C->G) mutation of the Agamma-globin gene has been evaluated by in vitro gene expression