MACROD2 and obesity due to melanocortin 4 receptor deficiency: Non-coding and structural mutations/variations in the germline MACROD2 gene have been associated with psychiatric disorders, obesity and cancer predisposition.18–20 Deletions in the MACROD2 gene are frequent in colorectal cancer21,22 and are reported to alter DNA repair and sensitivity to DNA damage and consequently impact colorectal tumorigenesis.23 Neither RNA expression nor functional studies support a tumour suppressor role of MACROD2 gene.