Childhood Obesity Strongly Influenced by Genes
Researchers say they have uncovered more evidence that genes contribute strongly to childhood obesity. The study results suggest childhood obesity has a strong genetic component and cannot be entirely attributable to inactivity, high calorie foods and other environmental causes as suggested by some public health experts.
Struan F.A. Grant, Ph.D., associate director of the Center for Applied Genomics (CAG) at The Children’s Hospital of Philadelphia lead the study that searched whole genomes of thousands of obese children for copy number variations, or CNVs. The study found variations that put individuals at very high risk for obesity.
Grant says, “Our study is the first large-scale, unbiased genome-wide scan of CNVs in common pediatric obesity. We found CNVs that were exclusive to obese children across two ethnicities—European Americans and African Americans.”
Role of Genes in Childhood Obesity adds to Puzzle
According to background information from the study, 70 percent of children grow up to become obese adults. Childhood and adult obesity has become increasingly more prevalent over the past ten years. The researchers say the role of genes in childhood obesity adds to the puzzle of understanding obesity in children.
Most of the CNV's found have not been previously linked to obesity. In the current study the researchers found deletions or duplications of DNA sequences in 1,080 obese children that they were unable to find in a control of 2,500 lean children from European American descent.
Next, the scientists studied 1,479 obese and 1,575 lean African-American children exclusively, finding that half of the CNVs found in European American children were also present in obese African-Americans. All of the children were between age 2 and 18.
Co-author of the study, Hakon Hakonarson, M.D., Ph.D explains, “Because many gene variants have different frequencies in different ethnic groups, detecting these same CNVs in both groups, exclusively in obese subjects, strengthens the probability that these CNVs play a genuine role in the development of obesity."
The findings add strength that genes play a strong role in childhood obesity. Ongoing studies could lead to prevention and treatment if researchers uncover the biological mechanism of how genes contribute to obesity in children that also leads to higher risk of heart disease and type 2 diabetes.
The American Journal of Human Genetics