A brief report (NEJM 2015; 372: 48-54) details a case of 2.5 year old who weighed 33.7 kg (>99.9% and z score of 7.2) and had BMI of 38.6 (>99.9% and z score of 5.8).

Link to article (and picture/growth curve)

The authors determined that he had a mutation which caused biologically inactive leptin.  Subsequently, treatment with metreleptin injections, improved eating behavior and resulted in substantial weight loss.

Key points:

• “Current clinical recommendations advise that leptin serum concentrations be measured in children who have rapid weight gain in the first months of life.” (“The severely obese patient –a genetic work-up.” Nat Clin Pract Endocrinol Metab 2006; 2: 172-7)
• This case report demonstrates that normal circulating levels of the hormone “do not rule out disease-causing mutations in the gene encoding leptin.”

Related blog posts:

• Lower leptin with physical activity | gutsandgrowth
• Staggering cost of obesity | gutsandgrowth
• Is obesity neglect? | gutsandgrowth
• Is a Three Year-Old Too Young for Bariatric Surgery …