A recent study by the Center for Applied Genomics at The Children’s Hospital of Philadelphia and published in Nature Genetics has found that there are two genetic variations that seem to increase the risk of obesity among children. The study is the largest ever of its kind and takes a close look at the origins of this common – and deadly – childhood condition.
Data was collected from meta-analysis of 14 studies conducted in North America, Australia and Europe, involving 5,530 obese children and 8,318 non-obese children, comparing their 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,” stated lead investigator Struan F.A. Grant, PhD. “We saw a genetic signature for the disease.”
This study stands in contrast to previous research, which focused more heavily on extreme forms of childhood obesity and found it to be connected with rare diseases. In the most recent research, the team was able to identify two ‘new’ childhood obesity-related genes; one located near the OLFM4 gene on chromosome 13, and the other within the HOXB5 gene on chromosome 17.
According to statistics from the Centers for Disease Control and Prevention (CDC), obesity among children has more than tripled over the last 30 years, caused in large part by a caloric imbalance, which is just a fancy way of saying that kids are consuming more calories than they are expending.
Although physical activity levels, diet and environment are all factors in childhood obesity, the study implies a genetic connection as well.
“There is a genetic predisposition to childhood obesity, epidemiologists have been saying that,” Grant stated. “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.”
Grant went on to say that what is known at this point about the genes that were identified points toward intestinal function, although their precise role is still unknown. The study authors also hope that getting to the bottom of the genetic component in children should be simpler than doing so in adults, simply because environmental exposure has only gone on for a relatively short period of time.
It is also important to note that these genetic variations do not fully explain the epidemic of childhood obesity, and more research is necessary in order to understand the entire genetic impact. Researchers plan to look for additional factors that are related to obesity in order to gain a more complete picture of this issue, including incorporating children from a variety of ethnic backgrounds in future studies. The goal is to eventually design preventative interventions and treatments for children based on their individual genomes, but healthy lifestyle habits, including a balanced diet and regular exercise, will likely remain important components of warding off obesity, regardless of a person’s genetic predisposition.