Tests and diagnosis

By Mayo Clinic Staff

In infants, signs that may prompt your health care provider to request a blood test for Prader-Willi syndrome include:

  • Poor muscle tone and a weak cry
  • Poor sucking and feeding problems
  • Almond-shaped eyes and narrowing of the head at the temples
  • Problems with growth and development

In older children, your child's health care provider may suspect Prader-Willi syndrome if your child exhibits:

  • Excessive eating and weight gain
  • Underdeveloped sex organs
  • Short height and small hands and feet
  • Developmental delays
  • Intellectual disability
  • Thick and sticky saliva

A definitive diagnosis can almost always be made with a lab test. Special genetic tests can identify abnormalities in your child's chromosomes that indicate Prader-Willi syndrome.

April 17, 2014