Melanocortin 4 Receptor (MC4R) Deficiency

Abstract

An 18-year-old female student comes for an evaluation, accompanied by her parents. She has been considering bariatric surgery to manage her long-standing history of obesity. The patient reports that since early childhood, she has had ``weight issues.'' Her parents remember that at 12 months of age, she was always hungry and constantly seeking food. She was overweight as a toddler, but because of a history of overweight in her first paternal cousins, her parents did not think much of it. The patient's family has a very active lifestyle, which involves outdoor sports and hiking, so from an early age, she has been physically active. She currently plays lacrosse and field hockey at school, in addition to running 5 miles daily with her father. Her siblings -- one brother and a sister -- are lean, as well as the patient's mother. Her father is slightly overweight, in spite of his high activity level, and he was obese as a child. The patient feels that the most difficult part of trying to lose weight is controlling her appetite. She has food thoughts most of the time, and it is hard to stay on a low-carbohydrate diet. She is frustrated that no matter how much she exercises, she does not seem able to lose weight. At the moment, she weighs 120 kg, and her height is 1.80 m. The patient is much taller than her mother and siblings and as tall as her father. She currently takes no medications. Menarche was at age 13 and her menses are regular. She is doing well academically but feels her social life is restricted by her feeling ashamed of her weight. On her physical exam, her vital signs were within normal range. The patient looked her stated age. The exam revealed central adiposity but no dysmorphic features or acanthosis nigricans.