Lack of Association Between Vitamin D Receptor Genotypes and Haplotypes With Fat-Free Mass in Postmenopausal Brazilian Women

Lima, Ricardo Moreno; Abreu, Breno Silva de; Gentil, Paulo; Lins, Tulio Cesar de Lima; Grattapaglia, Dário; Pereira, Rinaldo Wellerson; Oliveira, Ricardo Jacó de

doi:10.1093/gerona/62.9.966

Cited by 28 publications

(14 citation statements)

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“…45 They can also be used in cross-sectional studies as covariates to adjust for a population stratification effect. 24 , 31 , 33 The use of ancestry informative markers to estimate individual ancestry is an effective and reliable solution to correct the effects of heterogeneity.…”

Section: Discussionmentioning

confidence: 99%

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Genetic Heterogeneity of Self-Reported Ancestry Groups in an Admixed Brazilian Population

Lins

Vieira

Abreu

et al. 2011

Journal of Epidemiology

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BackgroundPopulation stratification is the main source of spurious results and poor reproducibility in genetic association findings. Population heterogeneity can be controlled for by grouping individuals in ethnic clusters; however, in admixed populations, there is evidence that such proxies do not provide efficient stratification control. The aim of this study was to evaluate the relation of self-reported with genetic ancestry and the statistical risk of grouping an admixed sample based on self-reported ancestry.MethodsA questionnaire that included an item on self-reported ancestry was completed by 189 female volunteers from an admixed Brazilian population. Individual genetic ancestry was then determined by genotyping ancestry informative markers.ResultsSelf-reported ancestry was classified as white, intermediate, and black. The mean difference among self-reported groups was significant for European and African, but not Amerindian, genetic ancestry. Pairwise fixation index analysis revealed a significant difference among groups. However, the increase in the chance of type 1 error was estimated to be 14%.ConclusionsSelf-reporting of ancestry was not an appropriate methodology to cluster groups in a Brazilian population, due to high variance at the individual level. Ancestry informative markers are more useful for quantitative measurement of biological ancestry.

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Section: Discussionmentioning

confidence: 99%

“…The detailed optimized multiplex single-base extension protocol, with reactant concentration and PCR thermocycling conditions, has been reported elsewhere. 21 , 31 – 33 …”

Section: Methodsmentioning

confidence: 99%

Genetic Heterogeneity of Self-Reported Ancestry Groups in an Admixed Brazilian Population

Lins

Vieira

Abreu

et al. 2011

Journal of Epidemiology

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“…Subsequently, a minimum set of SNPs representing the original LD blocks was selected with a 90% prediction coverage (Lins et al , 2009). Sixteen SNPs were selected in addition to the five most studied VDR polymorphisms (rs11568820-Cdx2, rs10735810-FokI, rs1544410-BsmI, rs7975232-ApaI and rs731236-TaqI) used in our previous studies (Gentil et al , 2007, 2009; Lins et al , 2007, 2009; Moreno Lima et al , 2007). …”

Section: Methodsmentioning

confidence: 99%

Population analysis of vitamin D receptor polymorphisms and the role of genetic ancestry in an admixed population

et al. 2011

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The vitamin D receptor (VDR) is an essential protein related to bone metabolism. Some VDR alleles are differentially distributed among ethnic populations and display variable patterns of linkage disequilibrium (LD). In this study, 200 unrelated Brazilians were genotyped using 21 VDR single nucleotide polymorphisms (SNPs) and 28 ancestry informative markers. The patterns of LD and haplotype distribution were compared among Brazilian and the HapMap populations of African (YRI), European (CEU) and Asian (JPT+CHB) origins. Conditional regression and haplotype-specific analysis were performed using estimates of individual genetic ancestry in Brazilians as a quantitative trait. Similar patterns of LD were observed in the 5′ and 3′ gene regions. However, the frequency distribution of haplotype blocks varied among populations. Conditional regression analysis identified haplotypes associated with European and Amerindian ancestry, but not with the proportion of African ancestry. Individual ancestry estimates were associated with VDR haplotypes. These findings reinforce the need to correct for population stratification when performing genetic association studies in admixed populations.

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“…Dessa forma, pode ser argumentado que a não existên-cia de associação foi influenciada pela ancestralidade genômica. Nesse sentido, a genotipagem de polimorfismos informativos de ancestralidade e a consideração da ancestralidade genética estimada como covariável não alterou a associação observada em um estudo prévio do nosso grupo (Moreno Lima et al, 2007). Outra limitação do estudo refere-se a falta de mensuração do períme-tro da cintura, optando-se pela utilização apenas do DXA.…”

Section: Discussionunclassified

“…Para tal, utilizou-se o equipamento da marca Lunnar, modelo DPX-IQ (Lunar Corporation, Madison, WI, USA) conforme procedimentos previamente especificados por Moreno Lima et al (2007). Brevemente, as voluntárias foram posicionadas em decúbito dorsal sobre a mesa do equipamento, sendo em seguida cuidadosamente posicionadas de forma que ficassem totalmente centralizadas em relação às laterais da mesa.…”

Section: Instrumentos E Procedimentos Avaliação Da Composição Corporalunclassified

Estudo de associação entre polimorfismos no gene FTO e composição corporal em idosas brasileiras

Lunardi¹,

Pereira

Leite

et al. 2016

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RESUMOEstudos de associação genética (GWAS) sugerem uma importante contribuição do gene candidato FTO na composição corporal em diferentes populações e variada faixa etária. Este estudo teve como objetivo examinar a associação entre os polimorfismos no gene FTO (rs9939609 e rs1861868) e fenótipos de adiposidade em uma amostra de idosas brasileiras não caucasianas. A amostra foi composta por 241 mulheres (66.65± 5.5 anos). Os dados referentes à composição corporal foram mensurados através da absorciometria por raios-x de dupla energia (DXA) e a genotipagem dos SNPs foi realizada utilizando o sistema SnaPShot Multiplex System (Applied Biosystems). Não foram encontradas diferenças estatisticamente significativas para as variáveis de composição corporal entre os polimorfismos estudados, mesmo após o ajuste para ancestralidade Africana. Especificamente, índice de massa corporal (p= 0.94 e p= 0.66), percentual de gordura (p= 0.42 e p= 0.93) e massa livre de gordura total (p= 0.75 e p= 0.30), sendo os valores de p referentes aos rs9939609 e rs1861868, respectivamente. Nesta amostra de idosas brasileiras os polimorfismos do gene FTO (rs9939609 e rs1861868) não apresentaram associação com fenótipos de obesidade.Palavras-chave: genética, obesidade, idosos, mulher, densitometria, IMC, gene FTO ABSTRACT GenomeWide Association Studies (GWAS) suggest an important contribution of gene FTO in body composition and muscle strength in different populations and wide age. This study intended to examine the association of polymorphisms in the FTO gene (rs9939609 and rs1861868) with obesity phenotypes in a sample of Brazilian elderly women not Caucasian. The sample included 241 older women. Data concerning body composition were measured by dual energy X-ray absorptiometry (DXA) and genotyping of SNPs was carried out using the system snapshot Multiplex System (Applied Biosystems). There was no statistically significant difference for body composition variables, even after adjustment for African ancestry. Specifically, body mass index (p= 0.94 and p= 0.66), fat percentage (p= 0.42 and p= 0.93) and total fat free mass (p= 0.75 and p= 0.30) did not present significant differences between genotypes (p values related to rs9939609 and rs1861868, respectively). In this sample of Brazilian elderly, the studied FTO gene polymorphisms (rs9939609 and rs1861868) are not associated with obesity-related phenotypes.

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Lack of Association Between Vitamin D Receptor Genotypes and Haplotypes With Fat-Free Mass in Postmenopausal Brazilian Women

Cited by 28 publications

References 43 publications

Genetic Heterogeneity of Self-Reported Ancestry Groups in an Admixed Brazilian Population

Genetic Heterogeneity of Self-Reported Ancestry Groups in an Admixed Brazilian Population

Population analysis of vitamin D receptor polymorphisms and the role of genetic ancestry in an admixed population

Estudo de associação entre polimorfismos no gene FTO e composição corporal em idosas brasileiras

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