@article {6627, title = {Investigation of gene-by-sex interactions for lipid traits in diverse populations from the population architecture using genomics and epidemiology study.}, journal = {BMC Genet}, volume = {14}, year = {2013}, month = {2013}, pages = {33}, abstract = {

BACKGROUND: High-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglyceride (TG) levels are influenced by both genes and the environment. Genome-wide association studies (GWAS) have identified ~100 common genetic variants associated with HDL-C, LDL-C, and/or TG levels, mostly in populations of European descent, but little is known about the modifiers of these associations. Here, we investigated whether GWAS-identified SNPs for lipid traits exhibited heterogeneity by sex in the Population Architecture using Genomics and Epidemiology (PAGE) study.

RESULTS: A sex-stratified meta-analysis was performed for 49 GWAS-identified SNPs for fasting HDL-C, LDL-C, and ln(TG) levels among adults self-identified as European American (25,013). Heterogeneity by sex was established when phet < 0.001. There was evidence for heterogeneity by sex for two SNPs for ln(TG) in the APOA1/C3/A4/A5/BUD13 gene cluster: rs28927680 (p(het) = 7.4 x 10(-7)) and rs3135506 (p(het) = 4.3 x 10(-4)one SNP in PLTP for HDL levels (rs7679; p(het) = 9.9 x 10(-4)), and one in HMGCR for LDL levels (rs12654264; p(het) = 3.1 x 10(-5)). We replicated heterogeneity by sex in five of seventeen loci previously reported by genome-wide studies (binomial p = 0.0009). We also present results for other racial/ethnic groups in the supplementary materials, to provide a resource for future meta-analyses.

CONCLUSIONS: We provide further evidence for sex-specific effects of SNPs in the APOA1/C3/A4/A5/BUD13 gene cluster, PLTP, and HMGCR on fasting triglyceride levels in European Americans from the PAGE study. Our findings emphasize the need for considering context-specific effects when interpreting genetic associations emerging from GWAS, and also highlight the difficulties in replicating interaction effects across studies and across racial/ethnic groups.

}, keywords = {Female, Genetic Heterogeneity, Genome, Human, Genome-Wide Association Study, Humans, Lipids, Male, Polymorphism, Single Nucleotide, Population Groups}, issn = {1471-2156}, doi = {10.1186/1471-2156-14-33}, author = {Taylor, Kira C and Carty, Cara L and Dumitrescu, Logan and B{\r u}zkov{\'a}, Petra and Cole, Shelley A and Hindorff, Lucia and Schumacher, Fred R and Wilkens, Lynne R and Shohet, Ralph V and Quibrera, P Miguel and Johnson, Karen C and Henderson, Brian E and Haessler, Jeff and Franceschini, Nora and Eaton, Charles B and Duggan, David J and Cochran, Barbara and Cheng, Iona and Carlson, Chris S and Brown-Gentry, Kristin and Anderson, Garnet and Ambite, Jose Luis and Haiman, Christopher and Le Marchand, Lo{\"\i}c and Kooperberg, Charles and Crawford, Dana C and Buyske, Steven and North, Kari E and Fornage, Myriam} } @article {7465, title = {Trans-ethnic fine-mapping of genetic loci for body mass index in the diverse ancestral populations of the Population Architecture using Genomics and Epidemiology (PAGE) Study reveals evidence for multiple signals at established loci.}, journal = {Hum Genet}, volume = {136}, year = {2017}, month = {2017 Jun}, pages = {771-800}, abstract = {

Most body mass index (BMI) genetic loci have been identified in studies of primarily European ancestries. The effect of these loci in other racial/ethnic groups is less clear. Thus, we aimed to characterize the generalizability of 170 established BMI variants, or their proxies, to diverse US populations and trans-ethnically fine-map 36 BMI loci using a sample of >102,000 adults of African, Hispanic/Latino, Asian, European and American Indian/Alaskan Native descent from the Population Architecture using Genomics and Epidemiology Study. We performed linear regression of the natural log of BMI (18.5-70~kg/m(2)) on the additive single nucleotide polymorphisms (SNPs) at BMI loci on the MetaboChip (Illumina, Inc.), adjusting for age, sex, population stratification, study site, or relatedness. We then performed fixed-effect meta-analyses and a Bayesian trans-ethnic meta-analysis to empirically cluster by allele frequency differences. Finally, we approximated conditional and joint associations to test for the presence of secondary signals. We noted directional consistency with the previously reported risk alleles beyond what would have been expected by chance (binomial p~<~0.05). Nearly, a quarter of the previously described BMI index SNPs and 29 of 36 densely-genotyped BMI loci on the MetaboChip replicated/generalized in trans-ethnic analyses. We observed multiple signals at nine loci, including the description of seven loci with novel multiple signals. This study supports the generalization of most common genetic loci to diverse ancestral populations and emphasizes the importance of dense multiethnic genomic data in refining the functional variation at genetic loci of interest and describing several loci with multiple underlying genetic variants.

}, keywords = {Body Mass Index, Ethnic Groups, Genetics, Population, Humans, Obesity}, issn = {1432-1203}, doi = {10.1007/s00439-017-1787-6}, author = {Fernandez-Rhodes, Lindsay and Gong, Jian and Haessler, Jeffrey and Franceschini, Nora and Graff, Mariaelisa and Nishimura, Katherine K and Wang, Yujie and Highland, Heather M and Yoneyama, Sachiko and Bush, William S and Goodloe, Robert and Ritchie, Marylyn D and Crawford, Dana and Gross, Myron and Fornage, Myriam and B{\r u}zkov{\'a}, Petra and Tao, Ran and Isasi, Carmen and Avil{\'e}s-Santa, Larissa and Daviglus, Martha and Mackey, Rachel H and Houston, Denise and Gu, C Charles and Ehret, Georg and Nguyen, Khanh-Dung H and Lewis, Cora E and Leppert, Mark and Irvin, Marguerite R and Lim, Unhee and Haiman, Christopher A and Le Marchand, Lo{\"\i}c and Schumacher, Fredrick and Wilkens, Lynne and Lu, Yingchang and Bottinger, Erwin P and Loos, Ruth J L and Sheu, Wayne H-H and Guo, Xiuqing and Lee, Wen-Jane and Hai, Yang and Hung, Yi-Jen and Absher, Devin and Wu, I-Chien and Taylor, Kent D and Lee, I-Te and Liu, Yeheng and Wang, Tzung-Dau and Quertermous, Thomas and Juang, Jyh-Ming J and Rotter, Jerome I and Assimes, Themistocles and Hsiung, Chao A and Chen, Yii-Der Ida and Prentice, Ross and Kuller, Lewis H and Manson, JoAnn E and Kooperberg, Charles and Smokowski, Paul and Robinson, Whitney R and Gordon-Larsen, Penny and Li, Rongling and Hindorff, Lucia and Buyske, Steven and Matise, Tara C and Peters, Ulrike and North, Kari E} }