Ancestry informative SNPs can be useful to estimate individual and population biogeographical ancestry. Brazilian population is characterized by a genetic background of three parental populations (European, African, and Brazilian Native Amerindians) with a wide degree and diverse patterns of admixture. In this work we analyzed the information content of 28 ancestry-informative SNPs into multiplexed panels using three parental population sources (African, Amerindian, and European) to infer the genetic admixture in an urban sample of the five Brazilian geopolitical regions. The SNPs assigned apart the parental populations from each other and thus can be applied for ancestry estimation in a three hybrid admixed population. Data was used to infer genetic ancestry in Brazilians with an admixture model. Pairwise estimates of F(st) among the five Brazilian geopolitical regions suggested little genetic differentiation only between the South and the remaining regions. Estimates of ancestry results are consistent with the heterogeneous genetic profile of Brazilian population, with a major contribution of European ancestry (0.771) followed by African (0.143) and Amerindian contributions (0.085). The described multiplexed SNP panels can be useful tool for bioanthropological studies but it can be mainly valuable to control for spurious results in genetic association studies in admixed populations.

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.

Introduction For ostomized oncological patients, the physical body alterations affects the quality of life, as the changes in the self-concept are factors that directly affect the sexual life. Objective To analyze the perceptions of ostomized men due to intestinal cancer regarding sexual relations as an important dimension of quality of life, treated at the Ambulatory Care Program for Ostomized Patients of the Health Secretariat of the Federal District, Brazil. Methods Epidemiological-based study, of the analytical type, with a cross-sectional descriptive design, with quantitative and qualitative approach considering the content analysis. The convenience sample included 56 participants. Sociodemographic, clinical, and the WHOQOL-BREF questionnaires were used, as well as an individual interview. Data were analyzed by Microsoft Office Excel 2010 and SPSS 20.0 software. Statistical significance was set at 5%. Results The Physical, Social Relations and Environment Domains are correlated with the mean score, statistical significance (p < 0.0001), and the content analysis resulted in five categories: Ostomy, Self-Care, Acceptance, Self-concept, and Companionship. Conclusion Sexuality should be considered as a process of daily living of ostomized individuals due to intestinal cancer.

The current study investigated the association between vitamin-D-receptor (VDR) genotypes with bone-mineral density (BMD) and its interaction with physical activity level (PAL). Individuals in a sample of 192 volunteers (67.84 ± 5.23 years) underwent BMD evaluation and were genotyped for VDR ApaI, BsmI, FokI, and TaqI polymorphisms. Haplotypes were reconstructed through expectation-maximization algorithm, and regression-based haplotype-specific association tests were performed with studied phenotypes. None of the polymorphisms were associated with BMD at any site; however, haplotype was associated with femoral-neck and Ward’s-triangle BMD. Interaction between PAL and VDR genotypes was significant for the FokI polymorphism at femoral-neck and Ward’s-triangle BMD. The FokI T/T genotype was associated with higher BMD in active women. It was concluded that VDR haplotypes, but not genotypes, are associated with femoral-neck and Ward’s-triangle BMD in post-menopausal women. Moreover, the results suggest that VDR FokI polymorphism might be a potential determinant of BMD response to physical activity.

The relationship between vitamin D receptor (VDR) ApaI, CDX2, BsmI, FokI, and TaqI polymorphisms and fat-free mass (FFM) were examined in 191 postmenopausal Brazilian women (mean age 67.87 +/- 5.22 years). Participants underwent FFM measurements by dual-energy x-ray absorptiometry (DEXA). Whole-blood-extracted genomic DNA was genotyped to the aforementioned polymorphisms and to ancestry-informative markers through minisequencing, using the SNaPshot Multiplex System. Association between VDR polymorphisms and FFM variables was assessed by analysis of covariance. Haplotypes were estimated, and regression-based, haplotype-specific association tests were carried out with the studied phenotypes. No departure from Hardy-Weinberg equilibrium was detected for any polymorphism. None of the investigated VDR allelic variations, individually or analyzed as haplotypes, was associated with FFM phenotypes. The inclusion of individual African genomic ancestry was used as an attempt to correct for population stratification. Further studies in larger sample population are required to confirm these findings.