Genome-wide association of copy number variation identifies genetic
variants in childhood obesity using whole exome sequencing
Mi Yeong Hwang, Sanghoon Moon, and Bong-Jo Kim*
Division of Structural and Functional Genomics, Center for Genome Science, National
Institute of Health, Chungcheongbuk-do, 363-951, Korea
Obesity is a medical condition involving an excess amount of body fat. It is one of causes of
complex disease including Type 2 diabetes (T2D), cardiovascular diseases (CVD). Recently,
childhood obesity has rapidly increased due to lifestyle change. Copy number variations
(CNVs) are known for major sources of genetic variation along with single nucleotide
polymorphisms and these variants have been expected to associate with disease susceptibility.
Furthermore, some studies reported that CNVs are associated with extreme obesity.
In this study, we conducted case-control study to elucidate potential relationship between
CNVs and child obesity. To do this, we genotyped 682 individuals aged 12 to 16 years (353
boys and 329 girls) using whole exome sequencing approach with Agilent SSXT
V4+UTRs/Illumina Hiseq2500 (average depth of coverage 66.4x).
ExomeDepth which is a whole-exome sequencing-based CNV detection tool were used to
discover exonic CNVs. Subsequently, logistic regression was conducted using detected CNV
regions. Moreover, gene ontology and functional effectiveness were examined using
PANTHER and Variant Effect Predictor. Estimated CNV regions which reached statistical
significance were evaluated by quantitative PCR.
In conclusion, we found CNV regions associated with childhood obesity. This study may
provide useful insight into understanding genetic basis of childhood obesity.