Delayed diagnosis of proopiomelanocortin (POMC) deficiency with type 1 diabetes in a 9-year-old girl and her infant sibling

Abstract

Background: Proopiomelanocortin (POMC) protein, encoded by the POMC gene, is the precursor of adrenocorticotropic hormone (ACTH) that is released from the anterior pituitary gland. Homozygous mutations in the POMC gene is associated with hyperphagia, severe and early-onset obesity, adrenal insufficiency, hypopigmentation of the skin and red hair.

Case presentation: A 9-year-old girl from a consanguineous family of Iraqi origin was diagnosed with type 1 diabetes. She also had a tall stature. Her laboratory assessment showed low cortisol and ACTH concentrations, normal renin and poor response to ACTH stimulation. Genetic testing revealed a novel biallelic mutation in the POMC gene. Her sibling who had severe obesity and central adrenal insufficiency was found to be a carrier of the same mutation. Both siblings had alabaster-colored skin and brown hair.

Conclusions: POMC deficiency results in significant morbidity due to obesity, and it is also a potentially life threatening disease because of adrenal insufficiency. Therefore any suggestive symptom or sign of POMC deficiency warrants detailed investigations.

Keywords: adrenal deficieny; monogenic obesity; type 1 diabetes.