We found additional association regions, in normal weight versus obesity analysis, which were located upstream IRX3 (block 29 and 30, highest observed p value for rs1420285: χ2 = 10.84, p = 0.000994, OR = 1.338, 95% CI = 1.125–1.592) and downstream IRX6 (blocks 53 and 54 with highest observed p value for rs2171262: χ2 = 10.87, p = 0.000975, OR = 1.431, 95% CI = 1.155–1.772) in females only (Fig 3). This evidence concerns the gene IRX6 and obesity due to melanocortin 4 receptor deficiency.