title: Admixture mapping of quantitative trait loci for BMI in African Americans: evidence for loci on chromosomes 3q, 5q, and 15q.
abstract: Obesity is a heritable trait and a major risk factor for highly prevalent common diseases such as hypertension and type 2 diabetes. Previously we showed that BMI was positively correlated with African ancestry among the African Americans (AAs) in the US National Heart, Lung, and Blood Institute's Family Blood Pressure Program (FBPP). In a set of 1,344 unrelated AAs, using Individual Ancestry (IA) estimates at 284 marker locations across the genome, we now present a quantitative admixture mapping analysis of BMI. We used a set of unrelated individuals from Nigeria to represent the African ancestral population and the European American (EA) in the FBPP as the European ancestral population. The analysis was based on a common set of 284 microsatellite markers genotyped in all three groups. We considered the quantitative trait, BMI, as the response variable in a regression analysis with the marker location specific excess European ancestry as the explanatory variable. After suitably adjusting for different covariates such as sex, age, and network, we found strong evidence for a positive association with European ancestry at chromosome locations 3q29 and 5q14 and a negative association on chromosome 15q26. To our knowledge, this is the largest quantitative admixture mapping effort in terms of sample size and marker locus involvement for the trait. These results suggest that these regions may harbor genes influencing BMI in the AA population.
authors: Institute for Human Genetics, Department of Epidemiology and Biostatistics, University of California, San Francisco, California, USA.
authors: Analabha
authors: A
authors: Basu
authors: Hua
authors: H
authors: Tang
authors: Donna
authors: D
authors: Arnett
authors: C Charles
authors: CC
authors: Gu
authors: Tom
authors: T
authors: Mosley
authors: Sharon
authors: S
authors: Kardia
authors: Amy
authors: A
authors: Luke
authors: Bamidele
authors: B
authors: Tayo
authors: Richard
authors: R
authors: Cooper
authors: Xiaofeng
authors: X
authors: Zhu
authors: Neil
authors: N
authors: Risch
mesh_terms: D000328:Adult; D001741:Black or African American / Q000235:genetics*; D015992:Body Mass Index; D002884:Chromosomes, Human, Pair 15; D002893:Chromosomes, Human, Pair 3; D002895:Chromosomes, Human, Pair 5; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D018895:Microsatellite Repeats; D008875:Middle Aged; D009765:Obesity / Q000208:ethnology* / Q000235:genetics / Q000503:physiopathology; D010641:Phenotype; D040641:Quantitative Trait Loci; D012044:Regression Analysis; D014481:United States / Q000453:epidemiology; D044465:White People / Q000235:genetics*