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Admixture Mapping of Obesity‐related Traits in African Americans: The Atherosclerosis Risk in Communities (ARIC) Study
Author(s) -
Cheng ChingYu,
Reich David,
Coresh Josef,
Boerwinkle Eric,
Patterson Nick,
Li Man,
North Kari E.,
Tandon Arti,
BaileyWilson Joan E.,
Wilson James G.,
Kao W.H. Linda
Publication year - 2010
Publication title -
obesity
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.438
H-Index - 199
eISSN - 1930-739X
pISSN - 1930-7381
DOI - 10.1038/oby.2009.282
Subject(s) - ancestry informative marker , obesity , single nucleotide polymorphism , locus (genetics) , waist , genome wide association study , interquartile range , socioeconomic status , genetic admixture , atherosclerosis risk in communities , body mass index , medicine , demography , biology , genetics , genotype , cohort , environmental health , gene , population , sociology
Obesity is an important cause of morbidity and mortality worldwide. In the United States, the prevalence of obesity is higher in African Americans than whites, even after adjustment for socioeconomic status (SES). This leads to the hypothesis that differences in genetic background may contribute to racial/ethnic differences in obesity‐related traits. We tested this hypothesis by conducting a genome‐wide admixture mapping scan using 1,350 ancestry‐informative single‐nucleotide polymorphisms (SNPs) in 3,531 self‐identified blacks from the Atherosclerosis Risk in Communities (ARIC) study. We used these markers to estimate the overall proportions of European ancestry (PEAs) for each individual and then scanned for the association between PEA and obesity‐related traits (both continuous and dichotomous) at each locus. The median (interquartile range) PEA was 0.151 (0.115). PEA was inversely correlated with continuous BMI, weight, and subscapular skinfold thickness, even after adjusting for socioeconomic factors. In contrast, PEA was positively correlated with BMI‐adjusted waist circumference. Using admixture mapping on dichotomized traits, we identified a locus on 2p23.3 to be suggestively associated with BMI (locus‐specific lod = 4.11) and weight (locus‐specific lod = 4.07). After adjusting for global PEA, each additional copy of a European ancestral allele at the 2p23.3 peak was associated with a BMI decrease of ∼0.92 kg/m 2 ( P = 2.9 × 10 −5 ). Further mapping in this region on chromosome 2 may be able to uncover causative variants underlying obesity, which may offer insights into the control of energy homeostasis.