An Observational,Prospective Natural History Study of Early-Onset Extreme Obesity Due to Bi-Allelic Loss-of-Function Mutations in the POMC, PCSK1 or LEPR Genes

This is an observational study. There are no protocol-defined visits, although patients are expected to have routine office visits approximately every 6 months. Upon signing of informed consent/assent and study enrollment, historical data will be abstracted from the patient's medical chart. The patient will then be observed prospectively for up to 5 years, with additional data collected from routine healthcare encounters and direct-to-patient questionnaires (where local laws allow), including laboratory tests, physical exam and patient reported outcomes/quality of life measures. Patients will be consented/assented to provide blood samples for biomarker assessments, DNA sequencing and archiving.