Thus, the presence of the A allele is associated with the geographical origin of the African component of the studied population. In the case of Brazil, Bantu haplotype predominates in all regions, followed by the Benin haplotype, which in turn is more common in Rio de Janeiro and Bahia, reflecting the significant presence of subjects from Central West Africa, where the Benin haplotype predominates. The Senegal and Cameroon haplotypes have low frequencies in almost all regions of Brazil. However, a relatively high frequency of the Senegal haplotype
(12%) has been Androgen Receptor Antagonist found in the state of Pará, northern Brazil , a finding that corroborates historical records of direct slave trade from Africa to Brazil. Therefore, the observed positive association between rs7482144 and HbF levels in SCA patients in this study can be considered an expected result, based on the prevalence of the Senegal haplotype in this population. Similarly, the lack of association observed in other Brazilian patients  is also consistent with the distribution of beta-S
haplotypes in the state of Pernambuco, northeastern www.selleckchem.com/products/PLX-4032.html Brazil, where the Senegal haplotype is not found. The estimated ancestry for SCA patients showed a high degree of European, African and Native American admixture (39.6%, 29.6% and 30.8%, respectively), while for the general population of Belém, using a set 46 ancestry-informative insertion deletion polymorphisms, the mean proportions of ancestry were 53.7% European, 16.8% African and 29.5% Native American . Patients showed lower European contribution, but higher proportions of African and Native American ancestries than the general population. The pattern of ancestry displayed by patients with sickle cell anemia certainly influenced the distribution of OSBPL9 SNPs studied and demonstrates that studies of association between genetic modifiers, clinical and laboratory manifestations in Brazil should be controlled by ancestry. As mentioned earlier, this is a preliminary study to validate SNPs
that have been well elucidated in SCA patients with predominantly African or European ancestry, in a sample of admixed SCA patients from the Amazon region, resulting from the miscegenation among European, African and Native American. If modifiers are associated with genetic ancestry then the level of mixing SCA patients has obvious implications on the distribution of SNPs, and therefore on the levels of HbF and clinical manifestations. Thus, in Latin America populations, where individuals tend to be more mixed than in African–American populations, SCA patients can be considered as promising targets for admixture mapping of genetic modifiers of ancestry-associated SCA clinical or laboratory manifestations  and .