Congenital disorder of HO mainly includes abnormalities in the leptin‐melanocortin pathway, leading to monogenic obesity syndrome, such as Prada–Willi syndrome (PWS), melanocortin‐4 receptor (MC4R) defect, leptin or proopiomelanocortin (POMC) deficiency, and Bardet–Biedl syndrome. This evidence concerns the gene LEP and Bardet-Biedl syndrome.