Genomic ancestry and ethnoracial self-classification based on 5,871 community-dwelling Brazilians (The Epigen Initiative).
Brazil never had segregation laws defining membership of an ethnoracial group. Thus, the composition of the Brazilian population is mixed, and its ethnoracial classification is complex. Previous studies showed conflicting results on the correlation between genome ancestry and ethnoracial classification in Brazilians. We used 370,539 Single Nucleotide Polymorphisms to quantify this correlation in 5,851 community-dwelling individuals in the South (Pelotas), Southeast (Bambui) and Northeast (Salvador) Brazil. European ancestry was predominant in Pelotas and Bambui (median = 85.3% and 83.8%, respectively). African ancestry was highest in Salvador (median = 50.5%). The strength of the association between the phenotype and median proportion of African ancestry varied largely across populations, with pseudo R(2) values of 0.50 in Pelotas, 0.22 in Bambui and 0.13 in Salvador. The continuous proportion of African genomic ancestry showed a significant S-shape positive association with self-reported Blacks in the three sites, and the reverse trend was found for self reported Whites, with most consistent classifications in the extremes of the high and low proportion of African ancestry. In self-classified Mixed individuals, the predicted probability of having African ancestry was bell-shaped. Our results support the view that ethnoracial self-classification is affected by both genome ancestry and non-biological factors.
Fundação Oswaldo Cruz, Instituto de Pesquisas Rene Rachou, Belo Horizonte, Brazil.
M Fernanda
MF
Lima-Costa
London School of Hygiene and Tropical Medicine, Department of Infectious Disease Epidemiology, London, UK.
Laura C
LC
Rodrigues
Universidade Federal da Bahia, Instituto de Saúde Coletiva, Salvador, Brazil.
Maurício L
ML
Barreto
Universidade Federal de Minas Gerais, Instituto de Ciências Biológicas, Belo Horizonte, Brazil.
Mateus
M
Gouveia
Universidade Federal de Pelotas, Programa de Pós Graduação em Epidemiologia, Pelotas, Brazil.
Bernardo L
BL
Horta
Fundação Oswaldo Cruz, Instituto de Pesquisas Rene Rachou, Belo Horizonte, Brazil.
Juliana
J
Mambrini
Universidade Federal de Minas Gerais, Instituto de Ciências Biológicas, Belo Horizonte, Brazil.
Fernanda S G
FS
Kehdy
Universidade de São Paulo, Instituto do Coração, São Paulo, Brazil.
Alexandre
A
Pereira
Universidade Federal de Minas Gerais, Instituto de Ciências Biológicas, Belo Horizonte, Brazil.
Fernanda
F
Rodrigues-Soares
Universidade Federal de Pelotas, Programa de Pós Graduação em Epidemiologia, Pelotas, Brazil.
Cesar G
CG
Victora
Universidade Federal de Minas Gerais, Instituto de Ciências Biológicas, Belo Horizonte, Brazil.
Eduardo
E
Tarazona-Santos
D000328:Adult; D044383:Black People / Q000235:genetics; D001938:Brazil; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D066261:Epigen / Q000235:genetics*; D005006:Ethnicity / Q000235:genetics*; D005828:Genetics, Population / Q000379:methods; D023281:Genomics / Q000379:methods; D006801:Humans; D008137:Longitudinal Studies; D008875:Middle Aged; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D044465:White People / Q000235:genetics; D055815:Young Adult
D066261:Epigen