Bariatric surgery is often successful for treatment of severe obesity. The mechanisms of weight loss after bariatric surgery and the role of central energy homeostatic pathways in this weight loss process are not well understood. The study of individuals with complete loss of function of genes important in the leptin-melanocortin system may help establish the significance of these pathways for weight loss after bariatric surgery. We describe the outcome of bariatric surgery in an adolescent with compound heterozygosity and complete functional loss of both alleles of the melanocortin 4 receptor (MC4R). The patient underwent laparoscopic adjustable gastric banding and truncal vagotomy at 18 8 12 years of age, which resulted in initial, but not long-term weight loss. Our experience with this patient suggests that complete MC4R deficiency impairs response to gastric banding and results in poor weight loss after this surgery.

BackgroundHeterozygous mutations in melanocortin-4 receptor (MC4R) are the most frequent genetic cause of obesity. Bariatric surgery is a successful treatment for severe obesity. The mechanisms of weight loss after bariatric surgery are not well understood.MethodsNinety-two patients who had Roux-en-Y gastric bypass (RYGB) surgery were screened for MC4R mutations. We compared percent excess weight loss (%EWL) in the four MC4R mutation carriers with that of two control groups: 8 matched controls and with the remaining 80 patients who underwent RYGB.ResultsFour patients were heterozygous for functionally significant MC4R mutations. In patients with MC4R mutations, the %EWL after RYGB (66% EWL) was not significantly different compared to matched controls (70% EWL) and non-matched controls (60% EWL) after 1 year of follow-up.ConclusionsThis study suggests that patients with heterozygous MC4R mutations also benefit from RYGB and that weight loss may be independent of the presence of such mutations.

Risk of type 1 diabetes at 3 years is high for initially multiple and single Ab+ IT and multiple Ab+ NT. Genetic predisposition, age, and male sex are significant risk factors for development of Ab+ in twins.

The central melanocortin system is essential for the regulation of long-term energy homeostasis in humans. Rodent experiments suggest that this system also affects glucose metabolism, in particular by modulating peripheral insulin sensitivity independently of its effect on adiposity. Rare patients with complete genetic defects in the central melanocortin system can provide insight into the role of this system in glucose homeostasis in humans.We here describe the eighth individual with complete POMC deficiency and the first with coincidental concomitant Type I Diabetes, which provides a unique opportunity to determine the role of melanocortins in glucose homeostasis in human. Direct sequencing of the POMC gene in this severely obese patient with isolated ACTH deficiency identified a homozygous 5′ UTR mutation −11C>A which we find to abolish normal POMC protein synthesis, as assessed in vitro. HHS Public Access Author Manuscript Author ManuscriptAuthor Manuscript Author ManuscriptThe patient's insulin requirements were as expected for his age and pubertal developmental. This unique patient suggests that in humans, the central melanocortin system does not seem to affect peripheral insulin sensitivity, independently of its effect on adiposity.

Graves' disease is less common in prepubertal than pubertal children, and initial presentation with thyroid storm is rare. We report an 11-year-old prepubertal Hispanic girl who presented with a one-day history of respiratory distress, fever, and dysphagia. She had exophthalmos, a diffuse bilateral goiter and was agitated, tachycardic, and hypertensive. Nasal swab was positive for respiratory syncytial virus (RSV). She was diagnosed with thyroid storm and admitted to the pediatric intensive care unit. While infection is a known precipitant of thyroid storm and RSV is a common pediatric infection, to the best of our knowledge, this is the first reported case of RSV infection apparently precipitating thyroid storm in a prepubertal child.