Prader-Willi syndrome (PWS), a complex multisystem genetic disorder, is caused by the lack of expression of paternally inherited imprinted genes on chromosome 15q11-q13 1) . PWS has various characteristic features, including neonatal hypotonia, developmental delay, short stature, behavioral abnormalities, childhood-onset obesity, hypothalamic hypogonadism, and characteristic appearance 2). The course and early natural history of PWS patients can be divided into two generally recognized clinical stages. Symptoms of PWS include infantile hypotonia and failure to thrive in the neonatal and early infancy period, followed by life-long hyperphagia, developmental delays, moderate-to-severe behavioral problems, and several physical problems that impact health.Regarding on the hyperphagia period, PWS patients are unable to control food intake and will overeat if not monitored. Their food-seeking behaviors and low metabolic rate make them obese. Obesity is the greatest threat to their health, and these patients often die young from obesity-related complications. While no medications are currently known to aid in controlling hyperphagia, human growth hormone is used for the treatment of PWS because it can help normalize height, increase lean body mass and mobility, and decrease fat mass 3) . Other symptoms associated with PWS usually include cognitive challenges and learning disabilities, growth hormone deficiency and short stature, small hands and feet, scoliosis, sleep disturbances with excessive daytime sleepiness, high pain threshold, difficulties with speech and movement, and infertility. Behavioral difficulties may include obsessive-compulsive symptoms, skin picking, and difficulty controlling emotions. Treatments for many of these secondary complications include education planning, speech therapy, and growth and sex hormone replacement therapy. Serotonin reuptake inhibitors (SRIs) are also helpful for most teenagers and adults in managing mood-related symptoms.The complex genetics, etiology, multiple phenotypes, and evolving natural history of PWS suggest that a multidisciplinary professional, parental, societal, and environmental approach to the management of these patients is required for overcoming the many challenges of reducing morbidity and mortality and improving patient quality of life (QoL) 1) . The multidisciplinary team involved in the care of PWS patients and their families should include several medical and non-medical professional figures (e.g. child psychiatrists, pediatric endocrinologists, clinical geneticists, orthopedic specialists, educational psychologists, and social workers). However, all these professional figures should know what the patient wants and what kind of relationship there is between the traditional clinical outcome measures and the patient's perspective 4) . Over the last two decades, clinical researchers have emphasized the need for a thorough evaluation of the patient's QoL in order to study the impact of chronic illnesses and their treatments on the patient's life 5) . The ne...