A quantitative trait locus for body fat on chromosome 1q43 in French Canadians: linkage and association studies.
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.


METHODS
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 < or = 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.


CONCLUSIONS
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.
Aissani
Brahim
B
Human Genomics Laboratory, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA 70808, USA.
Perusse
Louis
L
Lapointe
Gilles
G
Chagnon
Yvon C
YC
Bouchard
Luigi
L
Walts
Brandon
B
Bouchard
Claude
C
D000273:Adipose Tissue / Q000378:metabolism*; D000293:Adolescent; D000328:Adult; D000368:Aged; D001823:Body Composition / Q000235:genetics*; D015992:Body Mass Index; D002878:Chromosomes, Human, Pair 1 / Q000235:genetics*; D015331:Cohort Studies; D005260:Female; D005787:Gene Frequency; D008040:Genetic Linkage; D005838:Genotype; D006306:Health Surveys; D006801:Humans; D008297:Male; D018895:Microsatellite Repeats; D008875:Middle Aged; D009765:Obesity / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D040641:Quantitative Trait Loci; D011792:Quebec