OBJECTIVES: We report X-chromosomal linkage disequilibrium (LD) patterns in Amerindian (Kogi, Wayuu, and Zenu) and admixed Latin American (Central Valley of Costa Rica and Southern Brazilian Gaucho) populations. METHODS: Short tandem repeats (STRs) widespread along the X-chromosome were investigated in 132 and 124 chromosomes sampled from the Amerindian tribes and the admixed Latin American populations, respectively. Diversity indexes (gene diversity and average numbers of alleles per locus) were estimated for each population and the level of LD was inferred with an exact test. RESULTS: The Amerindian populations presented lower genetic diversity and a higher proportion of loci in LD than the admixed ones. Two haplotype blocks were identified in the X-chromosome, both restricted to the Amerindians. The first involved DXS8051 and DXS7108 in Xp22.22 and Xp22.3, while the second found only among the Kogi, included eight loci in a region between Xp11.4 and Xq21.1. CONCLUSIONS: In accordance to previous work done with other populations, human isolates, such as Amerindian tribes, seem to be an optimal choice for the implementation of association studies due to the wide extent of LD which can be found in their gene pool. On the other hand, the low proportion of loci in LD found in both admixed populations studied here could be explained by events related to their history and similarities between the allele frequencies in the parental stocks.
OBJECTIVES: We report X-chromosomal linkage disequilibrium (LD) patterns in Amerindian (Kogi, Wayuu, and Zenu) and admixed Latin American (Central Valley of Costa Rica and Southern Brazilian Gaucho) populations. METHODS: Short tandem repeats (STRs) widespread along the X-chromosome were investigated in 132 and 124 chromosomes sampled from the Amerindian tribes and the admixed Latin American populations, respectively. Diversity indexes (gene diversity and average numbers of alleles per locus) were estimated for each population and the level of LD was inferred with an exact test. RESULTS: The Amerindian populations presented lower genetic diversity and a higher proportion of loci in LD than the admixed ones. Two haplotype blocks were identified in the X-chromosome, both restricted to the Amerindians. The first involved DXS8051 and DXS7108 in Xp22.22 and Xp22.3, while the second found only among the Kogi, included eight loci in a region between Xp11.4 and Xq21.1. CONCLUSIONS: In accordance to previous work done with other populations, human isolates, such as Amerindian tribes, seem to be an optimal choice for the implementation of association studies due to the wide extent of LD which can be found in their gene pool. On the other hand, the low proportion of loci in LD found in both admixed populations studied here could be explained by events related to their history and similarities between the allele frequencies in the parental stocks.
Authors: Joyce A Martins; Denise P Martins; Camila I F Oliveira-Brancati; Juliana Martinez; Regina M B Cicarelli; Dorotéia R S Souza Journal: Int J Legal Med Date: 2017-04-12 Impact factor: 2.686
Authors: Juliana Carla Gomes Rodrigues; Marianne Rodrigues Fernandes; André Maurício Ribeiro-Dos-Santos; Gilderlanio Santana de Araújo; Sandro José de Souza; João Farias Guerreiro; Ândrea Ribeiro-Dos-Santos; Paulo Pimentel de Assumpção; Ney Pereira Carneiro Dos Santos; Sidney Santos Journal: J Pers Med Date: 2022-06-10
Authors: Juliana Carla Gomes Rodrigues; Tatiane Piedade de Souza; Lucas Favacho Pastana; André Maurício Ribeiro Dos Santos; Marianne Rodrigues Fernandes; Pablo Pinto; Alayde Vieira Wanderley; Sandro José de Souza; José Eduardo Kroll; Adenilson Leão Pereira; Leandro Magalhães; Laís Reis das Mercês; Amanda Ferreira Vidal; Tatiana Vinasco-Sandoval; Giovanna Chaves Cavalcante; João Farias Guerreiro; Paulo Pimentel de Assumpção; Ândrea Ribeiro-Dos-Santos; Sidney Santos; Ney Pereira Carneiro Dos Santos Journal: PLoS One Date: 2020-04-15 Impact factor: 3.240