Mutations in the melanocortin-3 receptor (MC3R) gene: Impact on human obesity or adiposity.

The melanocortin-3 receptor (MC3R), together with the related melanocortin-4 receptor (MC4R), are important regulators of energy homeostasis. Rodent studies have demonstrated that the two receptors have non-redundant roles in regulating energy balance. However, while mutations for the MC4R have been established as a cause of monogenic obesity, mutations in the MC3R gene remain controversially associated with human obesity pathogenesis. This editorial summarizes the current status of MC3R in rodent energy homeostasis and human obesity pathogenesis.