Prader-Willi Syndrome

Prader-Willi syndrome is a rare genetic condition present from birth that causes constant, extreme hunger (hyperphagia), low muscle tone, and a very slow metabolism. People with this condition face lifelong challenges managing their weight and require specialised medical care.

Prader-Willi syndrome (PWS) is a complex neurodevelopmental disorder caused by loss of function of paternally expressed genes on chromosome 15q11-q13. The hallmark feature is hyperphagia — an insatiable drive to eat driven by hypothalamic dysfunction leading to absent satiety signalling and elevated ghrelin levels. PWS progresses through distinct nutritional phases: hypotonia with feeding difficulties in infancy, followed by weight gain without increased appetite, culminating in hyperphagia with severe obesity risk if food intake is not externally controlled.

Understanding rare conditions like PWS underscores the complexity of body weight regulation and the biological — not just behavioural — drivers of obesity. Dr Joseph Wang approaches every patient with an understanding that weight challenges have diverse and often complex underlying causes.