A new study by scientists at Council for Scientific and Industrial Research (CSIR) - Institute of Genomics and Integrative Biology and All India Institute of Medical Sciences in New Delhi have identified the potential role of two genes--ARID1A and KAT2B in the development of obesity.
Obesity or overweight is defined by the World Health Organization as having a Body Mass Index of over 30 Kg/m2. A WHO survey in 2015 of 195 countries identified over 600 million adults and around 100 million children as obese or overweight. The increased body weight is known to cause several health conditions including, cardiovascular diseases, diabetes and even some cancers.
Conventionally, the reasons identified for obesity was intake of energy-dense foods that are high in fat, salt and sugars and a decrease in physical activities. However, recent studies have shown a strong genetic basis for obesity and that certain populations have a stronger genetic predisposition to obesity compared to other populations 1.
In their new study, the scientists set out to study and identify the genes associated with obesity and overweight. 3,530 adolescent (age 11-17) participants were selected for the study, of which 2,539 were of normal weight and 991 were grouped under overweight/obese category. All the participants were from an Indian-European origin and were selected from school health surveys, from different parts of Delhi.
According to the study, obesity involves alterations in gene expressions that can change in response to genetic and environmental signals through chromatin modifications. Chromatin is a complex macromolecule containing DNA, proteins and RNA, and plays an important role in gene expression and DNA replication, preventing DNA damage and packaging the DNA in to a dense, compact shape. The scientists hypothesized that “genetic variations in chromatin modifier genes can predispose to obesity”
Further, the study identified two variants namely; rs6598860 and rs4589135 of the ARID1A gene having significant association with overweight/ obesity. It also revealed the association of the variant rs3804562 of the KAT2B gene with BMI.
According to the researchers “our data revealed that common variants of ARID1A and KAT2B are associated with increased susceptibility to overweight/obesity in Indian urban adolescents and provides a lead for future investigations toward understanding the contribution of epigenetic modifiers in genetic predisposition to obesity in adolescents”