Variantes estructurales de la hemoglobina en Iberoamérica / Structural variations of the hemoglobin in Iberoamerica

RESUMO

Structural hemoglobin variants are reviewed for Iberoamerica; specially in Latin America, they reflect racial composition and geographic origin. Latin American genetic composition is a function of ethnic composition in each country (mainly Africans and Spaniards, and the "indians" or native peoples). For this reason the distribution of hemoglobin variants has been greathy affected by the individual and population movements, specially as a result of the 18th and 19th century African slave trade. Scientific, sanitary, social and cultural factors explain (at least for Latin America and Portugal), a quantitative and qualitative subestimation of the structural variants of hemoglobin. In Spain, which has extensive research on the subject, the Caucasian variant number is known to be high, compared with Latin America and Portugal. Concerning origin and prevalence of hemoglobin polimorphism, the only established positive selection force is malaria falciparum. In Iberoamerica, the Hb S, as the major polimorphism and the HbC. have the greatest clinical and anthropological importance. Nevertheless, most variants are rare (found in an individual person or a particular family). Other minor Iberoamerica polimorphisms are the Hb E and D-Punjab, from Asia; and the Hb Korle-Bu, G-Philadelphia and A'2 from Africa.