Proopiomelanocortin DeficiencyE23.-

Proopiomelanocortin Deficiency, also known as OBAIRH, is a rare, monogenic, autosomal recessive endocrine disorder characterized by early onset obesity due to severe hyperphagia, pigmentary disorders, especially pale skin and red hair, and secondary hypocortisolism.

The disorder results from a mutation in the POMC gene, which codes for a preprotein that is processed into a number of bioactive peptides, including alpha-melanocyte-stimulating hormone (MSH) and ACTH.

Proopiomelanocortin (POMC) deficiency causes severe obesity that begins at a young age. In addition to obesity, people with this condition have low levels of a hormone known as adrenocorticotropic hormone (ACTH) and tend to have red hair and pale skin that is very sensitive to the sun.

Affected babies usually have a normal weight at birth, but are constantly hungry, which leads to excessive food intake (hyperphagia). The babies gain weight continuously and are severely obese by the age of 1 year. Those affected suffer from excessive hunger and remain obese for the rest of their lives. It is unclear whether these people are susceptible to weight-related diseases such as cardiovascular disease or type 2 diabetes.

In the neonatal period, those affected are prone to hypoglycemia, hyperbilirubinemia and cholestasis, which can lead to death if left untreated.

1. Graves LE et al. (2021) Proopiomelanocortin deficiency diagnosed in infancy in two boys and a review of the known cases. J Paediatr Child Health 57:484-490.