The effect of these SNPs on HbF levels

have been investigated mainly in patients with predominantly African or European ancestry. This study aimed to validate SNPs commonly studied (HBG2, rs748214; BCL11A, rs4671393; and HBS1L-MYB, rs28384513, rs489544 and rs9399137) and to analyze the effect of genetic admixture on the distribution of these SNPs in a sample of SCA patients from Belém, capital of Pará State, Brazilian Amazon. The sickle cell mutation GDC-0199 cell line is absent among Native American populations and was introduced into the American continent by gene flow from Africa during the Atlantic slave trade from the 16th to the 19th century. Africans mixed with Native Americans and Europeans to various extents across the continent, so that SCA patients exhibit different levels of admixture mainly European and Native American origin, as observed in the general population. In Brazil, although the populations of all geographic regions are the result of interbreeding between Europeans, Africans and Native Americans, there are slight differences in admixture proportions. European ancestry is the most prevalent GPCR & G Protein inhibitor in all urban populations, but is higher in the southeast and south, while in the Northeast, Midwest and Southeast, the African ancestry in general is the second most

prevalent. The Native American ancestry is higher in the North and in general more prevalent than the African contribution [5]. Thus, if genetic modifiers are associated with genetic ancestry then the level of mixing in SCA patients has obvious implications on

the distribution of SNPs, and therefore on the levels of HbF and clinical manifestations. Blood samples from Rucaparib SCA patients attended at the Center for Hemotherapy and Hematology of Pará Foundation — HEMOPA, in Belém, capital of Pará state, Northern Brazil, were selected for this study. HEMOPA is the reference center for diagnosis and treatment of hemoglobinopathies in the region. The frequency of the HBB*S gene in this population is estimated at 0.016 and the expected number of SCA patients in this population (384) is in accordance with the number of patients registered at HEMOPA, approximately 400 patients, at the time the samples were selected. Of the 240 patients initially selected those younger than 5 years and those under treatment with hydroxyurea™ were excluded resulting in a sample of 167 patients (47% of registered patients). Of the 167 study subjects, 89 (53.2%) were female. The mean (SD) age was 18.0 (10.6) years and the median age was 15.0 (IQR 10.0–24.0) years. HbF was measured by high performance liquid chromatography (HPLC) using equipment D10-Hemoglobin A1C Testing System (Bio Rad ®, France). The mean HbF level of the participants was 7.6% (SD 5.2) and the median was 6.6% (IQR 3.6–9.8%).