title: Association of genetic variants with self-assessed color categories in Brazilians.
abstract: The Brazilian population was formed by extensive admixture of three different ancestral roots: Amerindians, Europeans and Africans. Our previous work has shown that at an individual level, ancestry, as estimated using molecular markers, was a poor predictor of color in Brazilians. We now investigate if SNPs known to be associated with human skin pigmentation can be used to predict color in Brazilians. For that, we studied the association of fifteen SNPs, previously known to be linked with skin color, in 243 unrelated Brazilian individuals self-identified as White, Browns or Blacks from Rio de Janeiro and 212 unrelated Brazilian individuals self-identified as White or Blacks from São Paulo. The significance of association of SNP genotypes with self-assessed color was evaluated using partial regression analysis. After controlling for ancestry estimates as covariates, only four SNPs remained significantly associated with skin pigmentation: rs1426654 and rs2555364 within SLC24A5, rs16891982 at SLC45A2 and rs1042602 at TYR. These loci are known to be involved in melanin synthesis or transport of melanosomes. We found that neither genotypes of these SNPs, nor their combination with biogeographical ancestry in principal component analysis, could predict self-assessed color in Brazilians at an individual level. However, significant correlations did emerge at group level, demonstrating that even though elements other than skin, eye and hair pigmentation do influence self-assessed color in Brazilians, the sociological act of self-classification is still substantially dependent of genotype at these four SNPs.
authors.affiliation: Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
authors.forename: Danielle Fernandes
authors.initials: DF
authors.lastname: Durso
authors.affiliation: Laboratório de Genética e Hematologia Molecular, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Sergio Paulo
authors.initials: SP
authors.lastname: Bydlowski
authors.affiliation: Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
authors.forename: Mara Helena
authors.initials: MH
authors.lastname: Hutz
authors.affiliation: Coordenação de Pesquisa/Divisão de Farmacologia, Instituto Nacional do Câncer (INCA), Rio de Janeiro, RJ, Brazil.
authors.forename: Guilherme
authors.initials: G
authors.lastname: Suarez-Kurtz
authors.affiliation: Laboratório de Genômica Clínica, Faculdade de Medicina, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
authors.forename: Tiago R
authors.initials: TR
authors.lastname: Magalhães
authors.affiliation: Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil ; Laboratório de Genômica Clínica, Faculdade de Medicina, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
authors.forename: Sérgio Danilo Junho
authors.initials: SD
authors.lastname: Pena
mesh_terms: D001938:Brazil; D016000:Cluster Analysis; D005789:Genealogy and Heraldry; D056726:Genetic Association Studies; D014644:Genetic Variation; D015894:Genome, Human / Q000235:genetics; D005838:Genotype; D006801:Humans; D015810:Linkage Disequilibrium / Q000235:genetics; D010858:Pigmentation / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D025341:Principal Component Analysis; D012044:Regression Analysis; D012984:Software