April 8th, 2012
01:01 PM ET
Researchers have identified two genetic variations that appear to increase the risk of childhood obesity.
The study authors took data from North American, Australian and European meta-analysis of 14 studies consisting of 5,530 obese children and 8,318 non-obese kids. The team compared the genetic data.
“When we surveyed all the genetic variation across the obese children and non-obese children, some variants were highly, statistically, overrepresented in the obese cases. We saw a genetic signature for the disease,” said lead investigator Struan Grant, associate director of the Center for Applied Genomics at The Children’s Hospital of Philadelphia.
The team identified two new childhood obesity related genes, one near the OLFM4 gene on chromosome 13, the other within the HOXB5 gene on chromosome 17. Their results are published Sunday in Nature Genetics.
While nutrition, physical activity and environment are factors in childhood obesity, this study implies a genetic relationship.
“There is a genetic predisposition to childhood obesity, epidemiologists have been saying that,” Grant said. “The facts are bearing that out, as we see genetic variants associated with the trait. Some kids are obese, your genetic repertoire will interact with the environment. What your genetic load is will have a bearing on how your environment impacts your obesity risk.”
The authors reasoned that "distilling the genetic component ... should be easier in children, where environmental exposure and impact have occurred for a relatively short period in their lifetimes."
The team also identified some of the same genes in the data for obese kids as those detected in adult studies.
“We found some of those really kicked in early in life,” Grant said. “They’re strongly associated in children.”
But these genetic variations don’t fully explain childhood obesity, he warned.
The next step is to find more variants related to obesity to understand the full genetic picture. This study only involved children of European ancestry, so future studies would include kids of different ethnicities.
“These genetic variants give us new signposts in the genome for new biological insights into childhood obesity because we are beginning to understand the genetic architecture of the disease. It gives us new knowledge to develop new drug agents and treatments that will be more efficacious in treating this common disorder,” Grant said.
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