Prader Willi Syndrome (PWS) is a complex genetic disorder.  Most people with PWS have some degree of intellectual disability.  The first stage occurs during infancy and results in feeding and swallowing difficulties.  The second stage includes an obsession to eat, trouble pronouncing words, excessive sleepiness, decreased pain sensitivity, skin-picking habits, and slowed growths.  Those with PWS experience an insatiable appetite and excessive weight gain.