What are the symptoms of Prader-Willi syndrome?

Symptoms of Prader-Willi syndrome (PWS) are different in every person. Not everyone is affected the same way. Symptoms can also change with age.


  • Low muscle tone (hypotonia)
  • Difficulty sucking with trouble feeding
  • Distinct facial features, such as a narrow nasal bridge; almond-shaped eyes; narrow head; a turned-down mouth; and a thin upper lip
  • Delayed or poor development of motor skills, such as feeding, sitting up or walking

Childhood, teen years and adulthood

  • Constant food cravings and a slow metabolism. The cravings and slow metabolism can cause unhealthy weight gain or obesity if left unchecked.
  • Learning disabilities
  • Problems or delays in learning language
  • Behavioral issues
  • Little or no sex hormone production from the brain. This can cause small sex organs, incomplete or delayed puberty, and infertility (trouble reproducing later in life)
  • Short stature (short height)
  • Small hands and feet
  • Scoliosis (curved spine)
Rev. 4/2018. Reviewed by the MGfC Family Advisory Council.