About PWS

Prader-Willi syndrome has two distinct and opposite phases: infants are born weak having trouble feeding and are often underweight with a failure to thrive, while children with PWS move into a second phase at an age of typically two to five years,  where an extreme drive to consume food (also called ‘hyperphagia’) develops and persists throughout the person's lifetime. Children and adults eat voraciously and rapidly gain weight if their intake isn’t strictly controlled.

People with PWS also have short stature, poor muscle development, behavioural problems and a range of other characteristics. Many experience the co-morbidities of obesity, for e.g. type 2 diabetes and cardiovascular disease, which can lead to a shortened life span.

We understand that PWS is a complex genetic disorder, but the exact causal mechanisms are unclear. The syndrome is caused by absence of expression of about 100 genes in a discrete region on chromosome 15, which can affect the function of the hypothalamus. Prader-Willi syndrome is generally not heritable, but caused by a random genetic error or chromosomal absence.

  • Symptoms
  • Risks
  • Diagnosis & Treatment

Symptoms of PWS in babies include poor muscle tone, almond-shaped eyes, narrow forehead, a turned-down mouth and thin upper lip. Poor responsiveness and a weak sucking reflex can also be present, as well as underdeveloped genitals.

In children to adults, symptoms range from constant food cravings and weight gain, poor growth and motor development, possible cognitive impairment, and speech and behavioural difficulties.

There are no known risk factors for PWS. The disease is not inheritable.

Health checks for babies should pick up the early signs of poor feeding, growth and development associated with PWS, and should trigger genetic testing.

PWS has no cure, and there’s currently no drug-based treatment for excessive appetite. The only way to control appetite is through constant vigilance and supervision, behavioural restraints and environmental modifications like locked fridges and cupboards. Many adults with PWS would be able to live more independently (i.e. not in group homes) if there were effective treatments to curb their appetite.

This content is provided for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. If you have any concerns or questions about your health, please consult a suitably qualified healthcare professional.