title: A genome-wide association study of BMI in American Indians.
abstract: Numerous studies have been done to understand genetic contributors to BMI, but only a limited number of studies have been done in nonwhite groups such as American Indians. A genome-wide association study (GWAS) for BMI was therefore performed in Pima Indians. BMI measurements from a longitudinal study of 1,120 Pima Indians and 454,194 single-nucleotide polymorphisms (SNPs) from the 1 million Affymetrix SNP panel were used (35% of SNPs were excluded due to minor allele frequency <0.05). Data included BMI measured at multiple examinations collected from 1965 to 2004, as well as the maximum BMI at one of these visits. General and within-family tests were performed using a maximum-likelihood based mixed model procedure. No SNP reached a genome-wide significance level (estimated at P < 4.94 × 10(-7)). For repeated measures analyses, the strongest associations for general and within-family tests mapped to two different regions on chromosome 6 (rs9342220 (P = 1.39 × 10(-6)) and rs7758764 (P = 2.51 × 10(-6)), respectively). For maximum BMI, the strongest association for the general tests mapped to chromosome 4 (rs17612333; P = 1.98 × 10(-6)) and to chromosome 3 (rs11127958; P = 1.53 × 10(-6)) for the within-family tests. Further analysis is important because only a few of these regions have been previously implicated in a GWAS and genetic susceptibility may differ by ethnicity.
authors.affiliation: Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Phoenix, Arizona, USA. alka@niddk.nih.gov
authors.forename: Alka
authors.initials: A
authors.lastname: Malhotra
authors.forename: Sayuko
authors.initials: S
authors.lastname: Kobes
authors.forename: William C
authors.initials: WC
authors.lastname: Knowler
authors.forename: Leslie J
authors.initials: LJ
authors.lastname: Baier
authors.forename: Clifton
authors.initials: C
authors.lastname: Bogardus
authors.forename: Robert L
authors.initials: RL
authors.lastname: Hanson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D002877:Chromosomes, Human; D015331:Cohort Studies; D005190:Family; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D015894:Genome, Human; D055106:Genome-Wide Association Study / Q000379:methods; D005838:Genotype; D006801:Humans; D007198:Indians, North American / Q000235:genetics*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D008957:Models, Genetic; D009765:Obesity / Q000208:ethnology* / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D055815:Young Adult