Prader-Willi Syndrome is a rare genetic disorder that affects 1 in 10,000 people, causing physical and behavioral problems. It is caused by the lack of expression of paternal genes in a specific region of chromosome 15. Symptoms include low muscle tone, incomplete sexual development, cognitive disabilities, problem behaviors, and an insatiable appetite that can lead to obesity. Treatment aims to manage physical symptoms as well as providing behavioral and nutritional therapies.