Now in a fully revised and updated fourth edition, this book remains the most comprehensive resource on Prader-Willi syndrome (PWS) available on the market. There have been significant changes in the diagnosis, clinical care and treatment of PWS since the previous edition was published in 2006, and more thorough information on understanding the cause and diagnosis of the condition, along with clinical presentation and findings with natural history data now available. The book is divided into three thematic sections. Part One discusses the genetics, diagnosis, research and overview of PWS, including current laboratory testing. The medical physiology and treatment of PWS comprise Part Two, covering the GI system, obesity as well as the use of growth hormone. Part Three, the largest section, presents a wide-ranging, multidisciplinary management approach to PWS, attending to the many manifestations of the condition.