Variantes de hemoglobina en una población con impresión diagnóstica positiva para hemoglobinopatías en Colombia / Hemoglobin variants in Colombian patients referred to discard hemoglobinopathies

Background: Oxygen transport is altered in hemoglobinopathies. Aim: To study the distribution of hemoglobinopathies in Andean subjects without African ancestry. Material and Methods: We analyzed blood samples of 1,407 subjects aged 18 to 59 years (58% females), living in the central Andean region of Colombia, referred to discard hemoglobinopathies. The frequency and type of hemoglobinopathy was established by capillary and agarose gel electrophoresis. Results: The frequency of hemoglobinopathies was 34.5% and higher among females. The structural variants found were: AS-heterozygous hemoglobin (8.1%), homozygous SS (3.7%), heterozygous SC (2.2%), AC heterozygotes (0.5%) and heterozygous AE (0.3%). Quantitative variants found were Hb A-Beta thalassemia (13.91%) and Hb H (0.06%), Beta-thalassemia heterozygotes C (0.88%), S-Beta thalassemia heterozygotes (6.07%) and compound heterozygous SC/Beta thalassemia (0.25%), with a persistence of fetal hemoglobin 0. Composite thalassemia was also found in 31%. All techniques showed good correlation and capillary electrophoresis demonstrated a greater detection of hemoglobin variants. Conclusions: The frequency of hemoglobin variants in the analyzed population was high, which is an important public health indicator. The most common hemoglobin variant was HbA/Increased structural Hb A2 and the mos frequent structural hemoglobinopathy was sickle cell trait. Capillary electrophoresis can discern any Hb variants present in the population.

Determination of the prevalence of hemoglobin S, C, D, and G in neonates from Buenaventura, Colombia / Determinación de la prevalencia de la hemoglobina S, C, D y G en recién nacidos de Buenaventura, Colombia

Introduction: Inherited hemoglobinopathies are common among African Blacks. In Buenaventura, a city on Colombia’s Pacific coast, where 92% of the population is Afro-Colombian, there are few published attempts to identify these disorders. Affected individuals require more health care due to higher morbidity and mortality. Early identification of these newborns followed by comprehensive care is important to reduce co-morbidities. Objective: To study newborns and establish the numbers at risk with a bloodspot screening method. This information will demonstrate to Public Health Authorities the need to provide care for this population. Methods: A cross-sectional descriptive study of a sample of 399 newborns (95% CI) where there is an expected prevalence of 10% of abnormal hemoglobins. Mothers in at least the 36th week of gestation, living in the urban area of Buenaventura, were used. Umbilical cord blood was drawn and specimens fixed on filter paper and stored at 4°C. Isoelectric focusing electrophoresis assays were used to separate the hemoglobins. The results were reported according to the identified hemoglobin as F, A, S, C, D, and G. Results: We processed 399 samples, 353 (88.5%) were normal (hemoglobin FA), 23 (5.8%) were heterozygous for hemoglobin C (FAC), 19 (4.8%) were heterozygous for hemoglobin S (FAS), 2 (0.5%) were heterozygous for hemoglobin G (FAG), 1 was heterozygous for hemoglobin D (FAD) and 1 was heterozygous combined S and C (FSC). Conclusion: Hemoglobins S, C, D, and G are common among infants born in Buenaventura. Hemoglobin C occurred more frequently than in other reported studies. This study suggests that both detection and a follow-up program are required in areas with a high density of Afro-Colombian population.

Introducción: Las hemoglobinopatías son entidades muy frecuentes en el África negra. En Buenaventura, ciudad de la costa pacífica colombiana con una población 92% afrocolombiana, hay pocas publicaciones identificando esta patología. Las poblaciones afectadas requieren cuidados especiales por su alta mortalidad y morbilidad. La identificación temprana desde el periodo neonatal y los programas de cuidado integral se imponen en poblaciones de alta prevalencia. Objetivo: Determinar la prevalencia en Buenaventura de hemoglobinas S, C, D y G con un modelo de tamizaje neonatal. La información colectada servirá para sustentar recomendaciones a las autoridades de salud pública. Metodología: Se realizó un estudio descriptivo de corte transversal en 399 neonatos para una prevalencia esperada del 10% (IC 95%), con madres residentes del área urbana de Buenaventura y 36 semanas o más de gestación. Se tomó muestra de sangre de cordón umbilical fijada en papel filtro y almacenada a 4°C. La técnica de electroforesis de punto isoeléctrico sirvió para la separación de las hemoglobinas. Los resultados se informaron de acuerdo a las hemoglobinas identificadas F, A, S, C, D y G.Resultados: Se procesaron 399 muestras de cordón. El 88.5% (353) de las muestras fueron normales (hemoglobina FA), 23 (5.8%) fueron heterocigotos para hemoglobina C (FAC), 19 (4.8%) fueron heterocigotos para hemoglobina S (FAS), 2 (0.5%) fueron heterocigotos para hemoglobina G (FAG), 1 fue heterocigoto para hemoglobina D (FAD) y 1 fue heterocigoto combinado S y C (FSC). Conclusión: Hemoglobinas S, C, D y G son frecuentes entre los neonatos de Buenaventura. La hemoglobina C fue más frecuente que en estudios previos, probablemente por sesgos en la selección de la muestra de dichos estudios. Se sugiere a las autoridades de salud pública la ampliación del programa de tamizaje de enfermedades congénitas como las hemoglobinopatías.

Analizan la incidencia de las hemoglobinopatías estructurales / Incidence of structural haemoglobinopathies in populations of the Iberian Peninsula and Canary Islands

Las hemoglobinopatías estructurales se consideran el error monogenético hereditario potencialmente mortal más común en el mundo. En los últimos 10-15 años su incidencia ha aumentado en España debido a la emigración de poblaciones desde zonas de alta prevalencia en el extranjero a otras de baja prevalencia en España. El objetivo de esta revisión ha sido recopilar los resultados de incidencia de hemoglobinopatías estructurales en Lanzarote, realizar una revisión bibliográfica de su prevalencia en las islas Canarias y discutir la incidencia de estos trastornos de la hemoglobina en España. Se realizó un estudio epidemiológico observacional transversal para determinar la prevalencia de hemoglobinopatías en 2 436 mujeres gestantes en Lanzarote. El método diagnóstico de tamizaje fue la electroforesis de hemoglobinas a pH alcalino. La prevalencia global de portadores de hemoglobinopatías estructurales fue 9.44 por mil. Se detectó hemoglobinopatía en 23 mujeres y la distribución fue: 13 tenían la variante S heterocigota, 7 eran portadoras de HbC, 2 de HbD y en un caso se halló hemoglobina inestable. Más del 82% de las hemoglobinas variantes correspondían a población inmigrante con origen en Africa y América. En conclusión, el aumento de la importancia de los portadores de hemoglobinopatías estructurales en España se justifica por el aumento del flujo de inmigración que se recibe en la comunidad canaria y otras regiones españolas desde países donde estas enfermedades son prevalentes. La posibilidad de tomar medidas preventivas tempranas justifica la puesta en marcha de programas de cribado neonatal y de escrutinio de portadores en la población infantil, así como en mujeres gestantes, para prevenir la aparición de las formas graves de la enfermedad.

Intervention and prevention of hereditary hemolytic disorders in India: a case study of two ethnic communities of Sundargarh district in Orissa.

OBJECTIVES: This study was aimed at to sensitize, motivate, and screen two major vulnerable tribal communities--Bhuyan and Kharia, for hemoglobinopathies and allied hemolytic disorders, along with prospective and retrospective genetic/marriage counseling to the affected persons. For sustainability, imparting of relevant training to local paramedical staff, and to undertake periodic follow up for evaluation, intervention and clinical management through local PHCs/hospitals. METHODOLOGY: Tribal people in Orissa live in clusters practicing inter-village marriages following tribal endogamy and clan exogamy. The random sampling procedure for the selection of whole village was followed. Population of each tribe was representative because incoming and outgoing married women represent other surrounding villages belonging to their community. The pre- and post-intervention knowledge, attitude and practice (KAP) studies were conducted. Sensitization, motivation and education for carrier detection were carried out through IEC materials, holding interactive meetings and discussions at district, block and village levels. Standard biochemical and hematological techniques were followed for analysis of blood samples. Relevant training to local health personnel was imparted. Both prospective and retrospective intervention and genetic/marriage counseling was done through local PHC doctor. RESULTS: Study revealed high occurrence of hemoglobinopathies in Bhuyan (9.8%) and Kharia (13.3%) tribes, including uncommon hemoglobin variants like hemoglobin D, E, beta-thalassemia, and hereditary persistence of fetal hemoglobin (HPFH). G-6-PD enzyme deficiency was high in Dhelki Kharia (30.7%) and in Dudh Kharia (19.2%), whereas, it was recorded to be 21.1%, 16.3% and 13.7% in Paraja, Paik and Paudi Bhuyan subtribes, respectively. Use of antimalarials was cautioned in these tribal communities. Due to low frequency of Rhesus (D) negative (0.2-1.2%), the Rhesus (D) incompatibility problem seemed to be absent. Impact of methodical and prudent intervention and preventive strategies was found positive and encouraging. CONCLUSIONS: Adoption of a biomedical anthropological approach for implementing and evolving health seeking cooperative strategy that was tribal-oriented, tribal-friendly and tribal-participatory for intervention and prevention of common hemolytic disorders was found effective. Success of this strategy was apparent with overwhelming response of tribal people towards changing the traditional mindset, improving the health and quality of life. Health must meet the needs and perception of the people.

Prevalência de talassemias e hemoglobinas variantes no estado de Goiás, Brasil / Prevalence of thalassemias and variant hemoglobins in the state of Goiás, Brazil

As anemias hereditárias, em especial as talassemias e hemoglobinas (Hb) variantes, são as mais comuns das alterações genéticas humanas; sua frequência na população brasileira é muito variável, dependendo dos grupos raciais formadores de cada região. O povoamento de Goiás, que teve início logo após o seu descobrimento, em 1726, motivado pela procura de ouro, foi composto principalmente por portugueses e escravos africanos, contexto que favoreceu a mestiçagem entre eles. Considerando que esses povos apresentam genes para as hemoglobinas anormais com frequências variadas, é esperado que se encontrem essas alterações genéticas na nossa população. O objetivo deste trabalho foi avaliar a a prevalência de talassemias e hemoglobinas variantes na população de Goiás. Para isso a casuística foi composta por 404 alunos participantes dos diversos cursos da Universidade Católica de Goiás (UCG), oriundos de 55 cidades do estado de Goiás. A prevalência de anemia hereditária por talassemias e hemoglobinas variantes em Goiás foi de 10,1 por cento, cuja ordem decrescente foi a seguinte: talassemia alfa heterozigótica (5,2 por cento), heterozigose para hemoglobina S (Hb AS) (2,2 por cento), heterozigose para hemoglobina C (Hb AC) (1 por cento), talassemia beta menor (0,7 por cento), associa��o entre talassemia alfa e heterozigose para Hb S (0,5 por cento), associação entre talassemia alfa e heterozigose para Hb C (0,3 por cento) e heterozigose para hemoglobina D (Hb AD) (0,3 por cento). Nenhum caso de homozigose foi encontrado no presente estudo. Este trabalho demonstrou a dispersão dos genes para Hb S, Hb C e Hb D, bem como de talassemias alfa e beta em uma população do estado de Goiás. Por essa razão, concluímos que é importante realizar programas com maior abrangência da população para estudo da epidemiologia das talassemias e hemoglobinas variantes no estado de Goiás.

The hereditary anemias, especially the thalassemies and hemoglobinopathies are the most common human genetic abnormalities. Their frequency in the Brazilian population is very variable depending on the racial groups typical of each region. The settlement of Goiás, that had its beginning after discovery in 1726 owing to the search for gold, was composed basically by Portuguese and African slaves, a context that favored the racial mixing among them. Considering that these groups present genes for abnormal hemoglobins with varied frequencies it is expected the finding of these genetic abnormalities within our population. The objective of this study was to evaluate the prevalence of thalassemies and variant hemoglobins in the population of Goiás. For this purpose the sample was composed by 404 participating students from several graduate courses of the Catholic University of Goiás originally from 55 cities of the state of Goiás. Laboratory tests were used taking into account the historical and demographic factors of the population. The prevalence of hereditary anemias by thalassemias and variant hemoglobins in Goiás was 10.1 percent, in which the decreasing order of these abnormalities was: alfa heterozygous thalassemy (5.2 percent); heterozygous hemoglobin S (Hb AS) (2.2 percent); heterozygous hemoglobin C (Hb AC) (1 percent); beta short thalassemy (0.7 percent); association between alpha thalassemy and heterozygous for hemoglobin S (0.5 percent); association between alpha thalassemy and heterozygous for hemoglobin C (0.3 percent); and heterozygous for hemoglobin D (0.3 percent). No homozygosity was found in the study group. This study demonstrates the need for large scale screening in human populations for epidemiological studies of the thalassemies and variant hemoglobins in the state of Goiás.

Triagem das hemoglobinopatias por isoeletrofocalizaçäo / Screening of hemoglobinopathies by isoelectric focusing

Com o propósito de verificar a aplicabilidade da isoeletrofocalizaçäo (IEF) na triagem populacional das hemoglobinopatias, analisamos dois grupos de amostras constituídos por 1.537 pacientes laboratoriais na faixa etária entre quatro meses e 71 anos e 303 amostras de sangue de recém-nascidos. Todos foram classificados pela cor da pele em caucasóides e negróides, e triados por métodos radicionais de identificaçäo de fenótipos das hemoglobinas, bem como por eletroforese com focalizaçäo isoelétrica. Os resultados, expressos pela soma das observaçöes nos dois procedimentos, evidenciaram que 3,9 por cento dos pacientes laboratorias (61 indivíduos) eram portadores de hemoglobinopatias, sendo o fenótipo prevalente o traço falciforme (2,8 por cento), seguido do traço da hemoglobina C (0,5 por cento) e da talassemia beta-heterozigota (0,4 por cento). Neste grupo, os negróides apresentaram 9,8 por cento de hemoglobinas anormais e os caucasóides, 2,5 por cento. Entre os recém-nascidos, 11,9 por cento (36 indivíduos) apresentaram hemoglobinopatias, com expressiva percentagem de fenótipo compatível com talassemia alfa (6,3 por cento), seguida da talassemia beta-heterozigota (3 por cento) e do traço falciforme (1,6 por cento). Neste grupo, os negróides apresentaram 35,3 por cento de hemoglobinas anormais e os caucasóides 7,1 por cento. A IEF evidenciou, para ambos 35,3 por cento de hemoglobinas anormais e os caucasóides, 7,1 por cento. A IEF evidenciou, para ambos os grupos, quatro indivíduos portadores de talassemia beta-heterozigota e 19 fenótipos compatíveis com talassemia alfa, sendo que, por isso, mostrou-se válida na visualizaçäo de fraçöes que säo pouco nítidas em outros sistemas eletroforéticos

Hemoglobinopatías en comunidades de raza negra de los ríos Cayapas y Onzoles, cantón Eloy Alfaro, provincia de Esmeraldas, Ecuador / Haemoglobinoapathies in black communities living along the banks of the rivers Cayapas and Onzoles, in the Eloy Alfaro canton, in the province of Esmeraldas, Ecuador

Se analizaron muestras de sangre de 1.364 individuos de raza negra pura, habitantes de la ribera de los ríos Cayapas y Onzoles, norte de la provincia de Esmeraldas, para hemoglobinopatías mediante electrofóresis de hemoglobina sobre acetato de celulosa y agar citrato. El 75,7 por ciento (1.032) de la población estudiada presenta hemoglobina normal y 24,3 por ciento (332) tiene variantes de hemoglobina. La variante más frecuente fue Hb.AS con 84,9 por ciento (282), seguida de Hb.AF 9,6 por ciento (32), Hb.SS 2,7 por ciento (9), Hb.FS 2,4 por ciento (8) y Hb.FF 0,3 por ciento (1). La prevalencia más elevada se detectó en los grupos de edad jóvenes, 0-9 años (31,8 por ciento) y 10-19 años (25,8 por ciento). Los hombres presentaron mayor prevalencia que las mujeres en los dos ríos estudiados y existen áreas geográficas características con alta prevalencia en el río Cayapas, Trinidad (45,5 por ciento) y Santa María (37,9 por ciento), mientras que en el río Onzoles la prevalencia es más uniforme. Se discuten los hallazgos encontrados, principalmente, la prevalencia del genotipo Hb.SS (2,7 por ciento) y de un caso (0,3 por ciento) con características de hb.FF que merecen ser estudiados con más detalle

Hemoglobinopatías en los países de la Cuenca del Caribe / Hemoglobinopathies in Caribbean Basin countries

A review hemoglobinopathies in the Caribbean basin, shows a clear association with race: In Costa Rica, evidence suggests two geographic origins for populations of African origin.