A Quantitative Trait Locus for Body Fat on Chromosome 1q43 in French Canadians: Linkage and Association Studies

Authors

  • Brahim Aissani,

    1. Human Genomics Laboratory, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana
    2. Present address: Department of Epidemiology, School of Public Health, University of Alabama, Birmingham, Alabama
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  • Louis Perusse,

    1. Division of Kinesiology, Department of Social and Preventive Medicine, Faculty of Medicine, Laval University, Sainte-Foy, Quebec, Canada
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  • Gilles Lapointe,

    1. Division of Kinesiology, Department of Social and Preventive Medicine, Faculty of Medicine, Laval University, Sainte-Foy, Quebec, Canada
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  • Yvon C. Chagnon,

    1. Molecular Psychiatric Genetic Unit, Robert-Giffard Laval University Research Center, Beauport, Quebec, Canada
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  • Luigi Bouchard,

    1. Division of Kinesiology, Department of Social and Preventive Medicine, Faculty of Medicine, Laval University, Sainte-Foy, Quebec, Canada
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  • Brandon Walts,

    1. Human Genomics Laboratory, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana
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  • Claude Bouchard

    Corresponding author
    1. Human Genomics Laboratory, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana
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Human Genomics Laboratory, Pennington Biomedical Research Center, Louisiana State University System, 6400 Perkins Road, Baton Rouge, LA 70808. E-mail: BouchaC@pbrc.edu

Abstract

Objective: To explore a quantitative trait locus (QTL) on human chromosome 1q affecting BMI, adiposity, and fat-free mass phenotypes in the Quebec Family Study cohort.

Research Methods and Procedures: Non-parametric sibpair and variance component linkage analyses and family-based association studies were performed with a dense set of chromosome 1q43 microsatellites and single-nucleotide polymorphism markers in 885 adult individuals.

Results: Linkage was observed between marker D1S184 and BMI (p = 0.0004) and with body fat mass or percentage body fat (p ≤ 0.0003), but no linkage was detected with fat-free mass. Furthermore, significant linkages (p < 0.0001) were achieved with subsamples of sibpairs at both ends of phenotype distributions. Association studies with quantitative transmission disequilibrium tests refined the linkage to a region overlapping the regulator of G-protein signaling 7 (RGS7) gene and extending to immediate upstream gene loci.

Discussion: The present study indicates that the QTL on chromosome 1q43 specifically affects total adiposity and provides a genetic mapping framework for the dissection of this adiposity locus.

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