We, therefore, designed a case-control study consisting of controls with normal oral glucose test (OGTT) and patients with pre-diabetes in an attempt to identify associations between T2DM and five genetic loci near NEGR1, GNPDA2, BDNF, MC4R and KCTD15 that have previously been reported to be associated with obesity or/and BMI [8]–[11]. This evidence concerns the gene MC4R and obesity due to melanocortin 4 receptor deficiency.