Heterozygous ACAN mutations result in a phenotypic spectrum ranging from mild and proportionate short stature to a mild skeletal dysplasia with disproportionate short stature and brachydactyly. Many affected individuals developed early-onset osteoarthritis and degenerative disc disease, suggesting dysfunction of the articular cartilage and intervertebral disc cartilage. Additional studies are needed to determine the optimal treatment strategy for these patients.

Background: Eating in the absence of hunger (EAH) is typically assessed by measuring youths' intake of palatable snack foods after a standard meal designed to reduce hunger. Because energy intake required to reach satiety varies among individuals, a standard meal may not ensure the absence of hunger among participants of all weight strata. Objective: The objective of this study was to compare adolescents' EAH observed after access to a very large food array with EAH observed after a standardized meal. Design: Seventy-eight adolescents participated in a randomized crossover study during which EAH was measured as intake of palatable snacks after ad libitum access to a very large array of lunchtype foods (.10,000 kcal) and after a lunch meal standardized to provide 50% of the daily estimated energy requirements. Results: The adolescents consumed more energy and reported less hunger after the large-array meal than after the standardized meal (P values , 0.001). They consumed '70 kcal less EAH after the large-array meal than after the standardized meal (295 6 18 compared with 365 6 20 kcal; P , 0.001), but EAH intakes after the large-array meal and after the standardized meal were positively correlated (P values , 0.001). The body mass index z score and overweight were positively associated with EAH in both paradigms after age, sex, race, pubertal stage, and meal intake were controlled for (P values 0.05). Conclusion: EAH is observable and positively related to body weight regardless of whether youth eat in the absence of hunger from a very large-array meal or from a standardized meal. This trial was registered at clinicaltrials.gov as NCT00631644.Am J Clin Nutr 2010;92:697-703.

Significant sexual dimorphisms in the manifestations of pubertal development are seen in obese girls and boys. Two known effects of obesity, increased peripheral conversion of low-potency androgens to estrogens by adipose tissue-aromatase and increased insulin resistance, may be in large part responsible for these differences.

Synopsis This paper reviews factors that contribute to excessive weight gain in children and outlines current knowledge regarding approaches for treating pediatric obesity. Virtually all of the known genetic causes of obesity primarily increase energy intake. Genes regulating the leptin signaling pathway are particularly important for human energy homeostasis. Obesity is a chronic disorder that requires long-term strategies for management. The foundation for all treatments for pediatric obesity remains restriction of energy intake with lifestyle modification. There are few long-term studies of pharmacotherapeutic interventions for pediatric obesity. Bariatric surgical approaches are the most efficacious obesity treatments but, because of their potential risks, are reserved for those with the most significant complications of obesity.