When we considered BMI as a continuous variable for the whole sample (BD and BDC groups), variants in intron 1 promoter flanking of FTO reached statistical significance (p < 0.05) and after diagnosis stratification this association remained only in the BD group (p < 0.05), even when the BDC group had a higher rate of obesity. The gene discussed is FTO; the disease is obesity due to melanocortin 4 receptor deficiency.