Monogenic obesity

Monogenic obesity is excess weight caused by a mutation in a single gene, as opposed to syndromic obesity not tied to a single gene variation and most obesity, which is caused by multiple genetic and environmental risk factors. Monogenetic obesity mostly affects the hypothalamus and leptin–melanocortin system (see hypothalamic obesity). However, it accounts for less than 5 percent of severe obesity cases. Known mutations leading to monogenetic obesity include:

• Leptin deficiency
• Leptin receptor deficiency
• Melanocortin-4 receptor (MC4R)
• Proopiomelanocortin (POMC
• Prohormone convertase 1/3 (PC1/3)
• SIM1
• BDNF
• NTRK2