Prader-Willi Syndrome (PWS) is a lifelong condition. A great deal of research is being done, but to date there is no cure. No reason is known for the genetic accident that causes this condition.

PWS is a rare and very complex, non-inherited genetic disorder. Several genes on chromosome 15 are deleted or unexpressed. The commonly observed characteristics include small hands and feet, abnormal growth and body composition (small stature, very low lean body mass and early onset childhood obesity), weak muscles, insatiable hunger, extreme obesity, intellectual disability and anxiety-driven behavioural outbursts. There is an underlying hormone deficiency. A definitive diagnosis is now available using genetic testing. PWS was first described by Swiss doctors Andrea Prader, Alexis Labhart and Heinrich Willi in 1956 based on the clinical characteristics of children they observed.

PWS symptoms are believed to be caused, in part, by a defect in the hypothalamus. This part of the brain is an important supervisory centre and hormone regulator. It controls metabolism of fats and carbohydrates, the development of muscle tone, the regulation of the sleep/wake cycle, body temperature, blood pressure, heartbeat, the expression of emotions, and many more functions of the body.

Symptoms caused by PWS vary throughout the person’s lifetime, and vary in severity from person to person. Infants fail to thrive and require health interventions to survive. Beginning some time in childhood, the brain fails to regulate appetite normally. For a person with PWS there is a constant pre-occupation with food accompanied by an unrelenting, overwhelming, overriding physiological drive to eat. Normal satiety (the feeling of fullness after eating) does not exist. The drive to eat is so powerful that most individuals will go to great lengths to eat large quantities of food. This leads to obesity. Next to hyperphagia – the insatiable drive for food – probably the most challenging symptoms caused by PWS are confabulation, heightened anxiety and erratic emotions and behaviour.

People with PWS are often easily frustrated, impulsive, quick to anger, rigid and concrete thinkers, and highly anxious. Throughout childhood and into adulthood, people with PWS will require the support of a multitude of professionals. Look at the page for Clinicians and Allied Health for more.

No known medication controls the hyperphagia, and very few medications successfully manage the behavioural symptoms. No one with PWS is able to live independently. Without 24/7 supervision for the entirety of their life, individuals may die prematurely as a result of choking, stomach rupture or tissue necrosis, or from complications caused by morbid obesity. There are however, treatments and management strategies that can help reduce or manage some of the symptoms caused by PWS and improve the quality of life. Look through the resources on this website for ideas, and to get help from the National Disability Insurance Scheme (NDIS) for Australians.

We are learning more about PWS every day, and there is hope. With increased knowledge and support, we can help all people with this condition to live a fuller life, despite their limitations.

More information about PWS characteristics can be found on international websites: