A genome-wide scan for body mass index among Nigerian families.
OBJECTIVE
Interest in mapping genetic variants that are associated with obesity remains high because of the increasing prevalence of obesity and its complications worldwide. Data on genetic determinants of obesity in African populations are rare.


METHODS
We have undertaken a genome-wide scan for body mass index (BMI) in 182 Nigerian families that included 769 individuals.


RESULTS
The prevalence of obesity was only 5%, yet polygenic heritability for BMI was in the expected range (0.46 +/- 0.07). Tandem repeat markers (402) were typed across the genome with an average map density of 9 cM. Pedigree-based analysis using a variance components linkage model demonstrated evidence for linkage on chromosome 7 (near marker D7S817 at 7p14) with a logarithm of odds (LOD) score of 3.8 and on chromosome 11 (marker D11S2000 at 11q22) with an LOD score of 3.3. Weaker evidence for linkage was found on chromosomes 1 (1q21, LOD = 2.2) and 8 (8p22, LOD = 2.3). Several candidate genes, including neuropeptide Y, DRD2, APOA4, lamin A/C, and lipoprotein lipase, lie in or close to the chromosomal regions where strong linkage signals were found.


CONCLUSIONS
The findings of this study suggest that, as in other populations with higher prevalences of obesity, positive linkage signals can be found on genome scans for obesity-related traits. Follow-up studies may be warranted to investigate these linkages, especially the one on chromosome 11, which has been reported in a population at the opposite end of the BMI distribution.
Adeyemo
Adebowale
A
Department of Pediatrics/Institute of Child Health, College of Medicine, University of Ibadan, Ibadan, Nigeria.
Luke
Amy
A
Cooper
Richard
R
Wu
Xiaodong
X
Tayo
Bamidele
B
Zhu
Xiaofeng
X
Rotimi
Charles
C
Bouzekri
Nourdine
N
Ward
Ryk
R
D000328:Adult; D015992:Body Mass Index; D002878:Chromosomes, Human, Pair 1; D002880:Chromosomes, Human, Pair 11; D002897:Chromosomes, Human, Pair 7; D002898:Chromosomes, Human, Pair 8; D005260:Female; D008040:Genetic Linkage; D006801:Humans; D008126:Lod Score; D008297:Male; D008875:Middle Aged; D009549:Nigeria / Q000453:epidemiology; D009765:Obesity / Q000453:epidemiology / Q000235:genetics*; D020080:Tandem Repeat Sequences