Objectives: Proopiomelanocortin (POMC) is the polypeptide precursor of several peptides including adrenocorticotropic hormone (ACTH), melanocyte stimulating hormone (MSH) and β-endorphin. POMC deficiency is a very rare disease characterized by adrenal insufficiency, early-onset obesity, and pigmentation abnormalities. Here we describe an 18 month old boy with central adrenal insufficiency, hypothyroidism, obesity and fair skin. Genetic analysis revealed a homozygous p.G99Afs*59 (c.296delG) mutation in the POMC gene.
Case: An 18 month old boy was referred for hypoglycemia. He was born to parents from close villages at 37 weeks gestation with a birth weight of 2,500 kg. Medical history revealed neonatal intensive care hospitalization for 28 days due to respiratory distress. He was admitted to emergency department with seizure. The laboratory tests revealed hypoglycemia (venous glucose:30 mg/dl), hyponatremia, hypocortisolism as well as hypothyroidism. Morning ACTH was <5 pg/mL, and cortisol was 0.488 μg/dl. Magnetic resonance imaging (MRI) of the brain and pituitary gland was normal. On his initial examination height SDS was 2.28 (90.5 cm), weight SDS was 3.34 (17.2kg) and BMI SDS was 2.46 (21 kg/m2). He was noted to have mild developmental delay, obesity, fair skin and hepatosplenomegaly. A homozygous p.G99Afs*59 (c.296delG) mutation in the POMC gene was detected. Thyroxine and hydrocortisone replacement was initiated.
Conclusions: Central adrenal insufficiency is rare in children. In our patient, p.G99Afs*59 mutation of the POMC gene results in ACTH deficicency subsequently leading to impaired adrenal steroidogenesis,dysregulation of food intake and early-onset obesity, increased linear growth, and melanocyte dysfunction. Early identification of these patients may enable early management of adrenal failure and its associated morbidities as well as severe obesity by novel therapeutic approaches.
27 Sep 2018 - 29 Sep 2018