Prevalência de talassemias e hemoglobinas variantes no estado de Goiás, Brasil

Abstract

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 Goias, 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 Goias. For this purpose the sample was composed by 404 participating students from several graduate courses of the Catholic University of Goias originally from 55 cities of the state of Goias. 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 Goias was 10.1%, in which the decreasing order of these abnormalities was: alfa heterozygous thalassemy (5.2%); heterozygous hemoglobin S (Hb AS) (2.2%); heterozygous hemoglobin C (Hb AC) (1%); beta short thalassemy (0.7%); association between alpha thalassemy and heterozygous for hemoglobin S (0.5%); association between alpha thalassemy and heterozygous for hemoglobin C (0.3%); and heterozygous for hemoglobin D (0.3%). 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 Goias.