[New insights about obesity-related genes].

Both genetic and environmental factors contribute to the development of obesity. Due to the progress in single nucleotide polymorphism (SNP) genotyping techniques, it is possible to conduct genome-wide screens to identify genetic variants associated with obesity. We reported that secretogranin III (SCG3) and myotubularin-related protein 9 (MTMR9) confer susceptibility to the obesity in the Japanese population. Variations in the insulin-induced gene 2 (INSIG2) and in the fat mass and obesity associated (FTO) genes are also associated with the obesity in the Japanese. These genes are expressed in the hypothalamus and have been indicated to play important roles in the food intake.