MC4R and obesity due to melanocortin 4 receptor deficiency: Correlation with 12-month percent total weight loss (%TWL) was assessed.<h4>Results</h4>FTO expression was significantly upregulated (mean fold-change: 4.68, p < 0.001) and MC4R downregulated (mean fold-change: - 0.91, p < 0.001) in patients with obesity.