HLA diversity in Brazil

Abstract

Brazil is the fifth largest country in the world in area and the fifth most populous. The Brazilian voluntary Bone Marrow Donor Registry is the third largest in terms of number of donors in the world, being a valuable source of HLA genetics to characterize the donor population of Brazil as well. The genetic background of the Brazilian population is quite heterogeneous, resulting from 5 centuries of admixture among Native Americans, Europeans and Africans, making the Brazilian population unique in terms of genetic ancestry. The unique characteristics of populations in different Brazilian regions make them an exciting focus for genetic diversity studies. Studies on HLA genetic diversity of Brazilian populations have been conducted since the late 1980s and, in this review, we highlight the main findings from studies carried out in Brazil based on classical HLA. In addition, we calculated the genetic distance from the molecular data of the studies included in this review in order to have a broader view of the HLA diversity in Brazilian populations. We emphasize that characterization of HLA diversity is not only important for transplantation programs, but can shed a light on ancestry, history and other demographic patterns with or without association with autoimmune disease.

HLA Genotypes and Type 1 Diabetes and Its Relationship to Reported Race/Skin Color in Their Relatives: A Brazilian Multicenter Study

“…All data regarding relatives were reported by the patients or their parents, which could make the data subject to error. Although reported skin color is considered a poor predictor of genomic ancestry in admixed populations, it gives an idea of the genetic structure of the Brazilian population [ 34 ]. In addition, it is important to highlight that the majority of epidemiologic studies carried out in Brazil have used self-reported race/skin color, which is therefore an important variable for comparing populations from different studies.…”

Inside the pocket: Critical elements of HLA‐mediated susceptibility to cervical precancerous lesions

“…9,10,[12][13][14]16,19,22,37,38 Recently, some GWAS confirmed the previously identified loci at 6p21.3-where the HLA region is located-as associated with CIN III 39 and CC 19,40 in European descent populations and a Chinese population. 41 However, the role of amino acids at specific positions of the HLA peptide-binding cleft was not extensively explored yet, 19,21 and there is no data F I G U R E 4 3D images of the peptide-binding cleft structure of HLA molecules built at the PyMol molecular graphics software, using the crystal structure of HLA-C (PDB ID: 5VGD) 30,31 (A, B) and HLA-DRB1 (PDB ID: 5NI9) 32,33 42 and each group present ancestry components from all of these groups. The average of each ancestry component (Americans, Africans, and Europeans) differs between groups, 42 but intragroup heterogeneity also exists.…”

Avaliação Da Frequência Alélica E Haplotípica Do Sistema Hla Para Os Loci Hla-A, Hla-B E Hla-Drb1 De Receptores Renais E Doadores Intervivo Do Estado Do Pará, Brasil/ Evaluation of the Allelic and Haplotypic Frequency of the Hla System for Hla-A, Hla-B E Hla-Drb1 Loci of Renal Receptors and Living Donors From the State of Pará, Brazil

“…A verificação da frequência dos alelos e haplótipos em diferentes populações foi realizada com comparativos entre artigos publicados, utilização de ferramentas de pesquisa alélica e haplotípica disponíveis nos sistemas de informação e base de dados allelefrequencies (www.allelefrequencies.net). (25,28). Além disso, carecem mais estudos sobre avaliação da diversidade HLA em candidatos a transplante renal na população brasileira.…”