Laboratório de Genética Humana e Médica, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, PA, Brazil.
Genet Mol Biol. 2012 Jul;35(3):553-6. doi: 10.1590/S1415-47572012005000041. Epub 2012 Jul 5.
The most common hemoglobinopathies, viz, hemoglobins S and C, and α- and β-thalassemias, were investigated through the molecular screening of 116 subjects from the community of Saracura, comprising fugitive African slaves from farms of the municipality of Santarém, in the west of Pará State, Brazilian Amazon. The observed frequency of the HBBS gene (0.9%) was significantly lower than that encountered in other Afro-derived communities in the region. Concomitantly, the absence of the HBBC allele has been reported for most of the Afro-Amazonian communities thus far studied. As remnant populations of quilombos are generally small, the heterogeneous distribution of HBBS and HBBC alleles among them is probably due to genetic drift and/or founder effect. The observed frequency of 3.7 kb deletion in Saracura (8.5%) was consistent with the African origin of the population, with a certain degree of local differentiation and admixture with individuals of Caucasian ancestry, placed in evidence by the occurrence of - -(MED) deletion (1.2%), a common mutation in Mediterranean regions. As regards β-thalassemia, among the seven different mutations found in Saracura, three β(o) and two β(+) mutations were of Mediterranean origin, and two β(+) of African. Thus, only 28% of the local β-thalassemia mutations found in Saracura were of African origin.
对来自巴西亚马逊州西部圣塔伦市（Santarém）各农场逃亡黑奴后裔聚居的萨拉萨村（Saracura）的 116 名居民进行了血红蛋白病分子筛查，结果发现了最常见的血红蛋白病，即血红蛋白 S 和 C 病，以及α-和β-地中海贫血。观察到 HBBS 基因的出现频率（0.9%）显著低于该地区其他非洲裔人群。此外，迄今为止研究过的大多数非裔亚马逊社区都未发现 HBBC 等位基因。由于逃亡黑奴的残余人口通常较少，因此 HBBS 和 HBBC 等位基因在其中的异质分布可能是由于遗传漂变和/或奠基者效应造成的。萨拉萨村（8.5%）中观察到的 3.7 kb 缺失频率与该人群的非洲起源一致，同时还存在一定程度的本地分化和与具有白种人血统个体的混合，这一点从 -(MED)缺失（地中海地区常见突变，1.2%）的发生情况中得到了证实。至于β-地中海贫血，在萨拉萨村发现的七种不同突变中，有三种β(o)和两种β(+)突变源自地中海地区，两种β(+)突变源自非洲。因此，萨拉萨村发现的当地β-地中海贫血突变中只有 28%源自非洲。
