Comments on: Lack of association between fat mass and obesity-associated genetic variant (rs8050136) and type 2 diabetes mellitus

Reply from the Author The first two third of the correspondence mentioned facts on the etiology of diabetes that are already described in details in the introduction and discussion parts of the article published by Yousuf et al.1 In human genetic association studies, cases group is selected based on the presence of the studied phenotype (in this case diabetes) and the control group is selected based on the absence of the studied phenotype (absence of diabetes=normal blood sugar based on fasting blood glucose and level of HbA1c). Among the environmental factors are sugar intake, tobacco use, level of physical activity, stress, sleep deprivation, obesity and many others. In human genetic association studies, it is impossible to control for all such factors. [...]the BMI point raised in the correspondence is also not valid.