Speech title: Association analysis explored substantial role of epistasis and ethnicity interactions in controlling BMI of MESA population
Abstract: Body Mass Index (BMI) is an important trait attributed by genetic effects and their environment interactions. In recent years, genetic behaviors of BMI has rarely been characterized for similarities and differences in the architecture for multi-ethnic groups. We conduct association analysis of BMI with genetic variants and their ethnic specific effects. Ten quantitative trait SNPs (QTSs) with individual genetic effects and also eight pairs of QTSs with epistasis effects were identified by analyzing BMI of multi-ethnic study of atherosclerosis (MESA) population. Estimated total heritability was 79.87% with higher contribution from dominance and dominance related epistasis effects (52.40%). Ethnicity specific genetics (GE) had large contribution to phenotypic variation (
44.83%). Genetic effects of the variants across and within different ethnic groups were investigated. We observed that at the several individual and epistasis loci, most Chinese-Americans (91% or more) carry negative effects. Compared with other ethnic groups, these may be the facts that BMI of group C-A is lower. The C-A specific genotypes of the loci were A/A of rs7763896 (
–0.42 for 100% C-A individuals), G/G of rs2504934 (
–2.59 for 99.25% C-A individuals), T/T of rs620175 (
–0.83 for 99.85% C-A individuals), G/G of rs6435678 (
–1.30 for 91.99% C-A individuals) and G/G×T/T of rs2504934 × rs620175 (
–0.37 for 99.10% C-A individuals). Conditional association analysis of BMI was conducted to investigate the impact of different lifestyle cofactors on BMI loci. We observed that the influence of lifestyle cofactors might depend on the genotype of the causal loci. In this analysis, we identified several new genes associated with BMI. Bioinformatics analysis using Biopubinfo showed that these genes are associated with several diseases, including high blood pressure, asthma, diabetes etc., while BMI has been shown to be a risk factor for these diseases.