Genomewide search for genes influencing percent body fat in Pima Indians: suggestive linkage at chromosome 11q21-q22. Pima Diabetes Gene Group.
On the basis of accumulating evidence that obesity has a substantial genetic component, a genomewide search for linkages of DNA markers to percent body fat is ongoing in Pima Indians, a population with a very high prevalence of obesity. An initial screen of the genome (>600 markers in 874 individuals) has been completed using highly polymorphic markers (mean heterozygosity = .67). Reported here are the sib-pair linkage results for percent body fat (277 siblings), the best available indicator of overall obesity. Single-marker linkages to percent body fat were evaluated by sib-pair analysis for quantitative traits. From these analyses, the best evidence of genes influencing body fat came from markers at chromosome 11q21-q22 and 3p24.2-p22 (P = .001; LOD = 2.0). Regions flanking these markers were further investigated by multipoint linkage. The evidence for linkage at 11q21-q22 increased to P = .0002 (LOD = 2.8), peaking between markers D11S2000 and D11S2366. Evidence for linkage at 3p24.2-p22 did not change. No association was detected for any marker in the region. Although several genes are known in the 11q21-q22 region, none have been implicated as candidate genes for obesity.
Norman
R A
RA
Clinical Diabetes and Nutrition Section, National Institute of Diabetes, Digestive, and Kidney Diseases, National Institutes of Health, Phoenix, AZ 85016-5319, USA. rnorman@phx.niddk.nih.gov
Thompson
D B
DB
Foroud
T
T
Garvey
W T
WT
Bennett
P H
PH
Bogardus
C
C
Ravussin
E
E
D000273:Adipose Tissue; D000328:Adult; D001823:Body Composition / Q000235:genetics*; D002874:Chromosome Mapping; D002880:Chromosomes, Human, Pair 11; D005260:Female; D008040:Genetic Linkage; D006801:Humans; D007198:Indians, North American / Q000235:genetics*; D008297:Male; D018895:Microsatellite Repeats; D008875:Middle Aged; D009765:Obesity / Q000235:genetics*; D013223:Statistics as Topic