OGG1 and obesity due to melanocortin 4 receptor deficiency: Obesity-associated insulin resistance is a major risk factor for type 2 diabetes,18 and fat accumulation has been reported to be associated with systemic oxidative stress19,20; therefore, it may be possible to assess the risk of diabetes based on the association between the Ser326Cys hOGG1 polymorphism and body mass index (BMI).