Genetics of obesity

Abstract

Genetic studies of obese animals and humans have led to findings of multiple genes that confer risk of developing obesity. Individuals can be classified as having genetic obesity, strong or slight genetic predisposition, or genetic resistance to obesity. The current evidence based on familial studies suggests that 40–80% of the variation between individual body mass indices has a genetic basis. The genetic reference tool ‘human obesity gene map’ provides a global encyclopaedia for identified genes, mutations, and qualitative trait loci. Studies such as genome-wide association studies have pointed researchers towards new pathways of neurohumoral mechanisms, other regulators of energy balance, and the interplay with the obesogenic environment. Gene studies have also unmasked the presence and significance of human microbiomes (particularly gut microbiomes) in the pathogenicity of obesity. The likelihood or presence of clinical obesity can be predicted in an individual through the use of genetic susceptibility with 60% accuracy. When gut microbiomes are identified, the predictive accuracy increases to 90%.