The substantial increase in the prevalence of obesity has created a global health crisis. In the United States, childhood obesity has tripled in recent decades, and the related healthcare costs have quadrupled. Obesity in children often leads to type 2 diabetes later in life, which is accompanied by costly, chronic health problems involving heart, kidney, and nerve damage from high blood sugar levels.
Recently, the significant contribution of genetic factors to obesity was revealed in genome-wide association studies (GWAS) done in adults. With funding from the Population Dynamics Branch, researchers used a powerful approach to search for childhood obesity genes by performing a large scale analysis that combined 14 existing GWAS studies for childhood obesity, totaling 5,530 cases.
The search identified seven genes, which were previously shown to be associated with body mass index in adults. These initial findings were then used to do a more rigorous analysis, which resulted in the identification of two new genes with a strong association specific to childhood obesity: OLFM4 (Olfactomedin 4) and HOXB5 (homeobox B5). Consistent with a role in obesity, the genes appear to make proteins that function in the stomach and intestines. To-date, these two genes show the strongest association with obesity in the first 18 years of life.
Comprehensive studies of these unique genes and the proteins they produce will be the next step toward a more complete understanding of the strong genetic component related to obesity in children and may offer clues for future therapeutic interventions (PMID: 22484627).