Obesity is an epidemic effecting the pediatric population. Currently, 17% of children are classified as obese and 32% as overweight. Many of these children develop complications including type 2 diabetes, dyslipidemia, hypertension and hepatic steatosis. Obesity is a global epidemic that lacks effective treatment options. Obesity has many underlying causes including genetic predisposition and environmental factors. Understanding the genetic basis of obesity may allow for more precisely targeted interventions including specific dietary plans and pharmacologic treatments. The most common cause of genetic obesity is haploinsufficiency of the melanocortin-4 receptor (MC4R). In obese adult cohorts, the prevalence of pathogenic MC4R mutations is 1-2%. Commercial testing is available for many obesity syndromes, but the cost is high and charges are not always covered by insurance. Clinicians have little motivation to test patients for MC4R mutations as no treatments are available and it is not clear if genetic testing results change patient behavior. This particular lab and other groups are working to develop novel pharmacologic treatments for obesity syndromes, such as MC4R deficiency. In order to better understand early onset obesity and to identify patients in interested in future research studies, including clinical trials, the investigators aim to develop a registry for patients with early onset obesity.