Genetics, surnames, grandparents' nationalities, and ethnic admixture in Southern Brazil: Do the patterns of variation coincide?

Abstract

A total of 2,708 individuals from the European-derived population of Rio Grande do Sul, divided into seven mesoregions, and of 226 individuals of similar origin from Santa Catarina were studied. Seventeen protein genetic systems, as well as grandparents' nationalities, individuals' surnames, and interethnic admixture were investigated. The alleles which presented the highest and lowest differences were GLO1*2 (16%) and PGD*A (2%), respectively, but in general no significant genetic differences were found among mesoregions. The values observed were generally those expected for individuals of European descent, with the largest difference being a lower prevalence (34-39%) of P*1. Significant heterogeneity among mesoregions was observed for the other variables considered, and was consistent with historical records. The Amerindian contribution to the gene pool of European-derived subjects in Rio Grande do Sul was estimated to be as high as 11%. Based on the four data sets, the most general finding was a tendency for a northeast-southwest separation of the populations studied. Seven significant phenotype associations between systems were observed at the 5% level (three at the 0.1% level). Of the latter, the two most interesting (since they were also observed in other studies) were MNSs/Duffy and Rh/ACP.

A review of psychiatric genetics research in the Brazilian population

“…76 On the other hand, in the southernmost State of Rio Grande do Sul, the overall admixture analysis showed again a pattern of European > Amerindian > African contribution, but the levels of admixture showed a vast majority (82%) of European ancestry, the degree of African and Native American admixture were 7% and 11% only. 77 In addition, a strong directional mating leading to an ethnic-related gender bias in the formation of our population was also demonstrated. Studies carried out with Brazilians classified as White have showed that their matrilineal ancestry evaluated by mitochondrial DNA haplogroups exhibits a rather equilibrate contribution among Amerindian, Europeans and African ancestries, 78 whereas the vast majority of Y chromosomes in white Brazilian males are of European origin (97.5%), with a surprisingly low frequency of African chromosomes (2.5%) and a complete absence of Native American contributions, 79 suggesting a preferential mating between European males and African and Amerindian females.…”

Pre- and Post-Columbian Gene and Cultural Continuity: The Case of the <i>Gaucho</i> from Southern Brazil

“…In contrast, in northern Brazil/Amazonia, the introduction of Amerindian genes into non-Native urban and rural populations is probably still occurring. The results of these continuous and discontinuous patterns of gene flow can be observed when comparing the mtDNA results mentioned above with the biparental loci admixture values ( ϳ 13% and ϳ 42% of Amerindian component for samples from the Pampa of Rio Grande do Sul and northern Brazilian/Amazonian region, respectively) [58,83] .…”

CFTR allelic heterogeneity in Brazil: historical and geographical perspectives and implications for screening and counseling for cystic fibrosis in this country

“…27 Studies of nuclear markers have shown that the overall (matrilineal and patrilineal) Amerindian contribution is lower, varying from 41% in the northern 28 to 7-11% in the southern regions. 29 Guarani and Kaingang are currently two of the most populous Amerindian groups in Brazil (41 000 and 22 000, respectively) and also the major Southern Brazilian Indian populations. They differ in multiple aspects of their cultures, and this correlates with the distinctiveness of their gene pools.…”