Prader-willi syndrome
Prader-Willi syndrome (PWS) is a variable and complex genetic neurobehavioral disorder resulting from abnormality on the 15th chromosome. It occurs in males and females equally and in all races. PWS typically causes low muscle tone, short stature, cognitive deficits, incomplete sexual development, problem behaviors, and a chronic feeling of hunger which, coupled with a metabolism that utilizes drastically fewer calories than normal, can lead to excessive eating and life-threatening obesity.