POMC (proopiomelanocortin) makes a protein that is cut into peptides that have different functions in the body. Adrenocorticotropic hormone (ACTH) is produced from the POMC protein and it helps maintain blood sugar levels, protects the body from stress, and stops inflammation.
Other peptides formed from POMC include: β-MSH peptide, which plays a role in weight regulation; α-MSH peptide, which helps maintain the correct energy balance; γ-MSH, which is involved in regulating the amount of sodium in the body and controlling blood pressure; and β-endorphin, which stimulates signaling for pain relief.
Several mutations in the POMC gene have been found in people with proopiomelanocortin (POMC) deficiency. These gene mutations lead to the production of an abnormally short version of the POMC protein or no protein at all. As a result, there is an absence of the peptides made from POMC, including ACTH, α-MSH, β-MSH, β-endorphin, and sometimes γ-MSH. Loss of these peptides prevents signaling through their receptor proteins and disrupts certain functions in the body. Without ACTH, there is a reduction in cortisol production, which leads to low blood sugar (hypoglycemia) and other problems in affected individuals. Decreased α-MSH in the skin reduces pigment production in melanocytes, which results in the red hair and pale skin often seen in people with POMC deficiency. Loss of signaling in the brain stimulated by α-MSH and β-MSH dysregulates the body's energy balance, leading to overeating and severe obesity. Shortage of γ-MSH or β-endorphin does not seem to cause health problems in people with this condition. The β-MSH peptide plays a role in weight regulation by binding to melanocortin 4 receptor (MC4R). Signaling through this receptor in the brain helps maintain the balance between energy from food taken into the body and energy spent by the body. The correct balance is important to control eating and weight.
If you carry the G-allele in this gene and you are female, then you are more predisposed to raised cortisol levels. The C-allele has been linked with obesity.
It is important to look at your genotype in this gene in conjunction with your LEPR, PPARG, PPARGC1, and MC42 genotypes.