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What Is Prader-Willi Syndrome?

Prader-Willi syndrome is a rare genetic disorder that affects growth, metabolism, appetite, behavior and overall development. Kids who have Prader-Willi syndrome have weak muscles, short stature, incomplete sexual development and chronic feelings of hunger.

Because children who have the syndrome also metabolize fewer calories than normal, the condition can lead to obesity. Prader-Willi syndrome is the most commonly known genetic cause of obesity.

About one in 15,000 children is born with Prader-Willi syndrome. The condition affects males and females of every race equally. Only 1 percent of kids who have the syndrome also have a family history of the condition.


What Causes Prader-Willi Syndrome?

Prader-Willi syndrome is caused by abnormalities in one or more genes in part of chromosome 15. However, experts don’t know which specific genes contain the errors.

Normally, each parent passes a copy of chromosome 15 to their child. A majority of children who have Prader-Willi syndrome are missing genetic material on some part of the father’s chromosome.

The genetic errors that cause Prader-Willi syndrome occur in one of three ways:

  • Genes that a child normally inherits from the father for chromosome 15 are missing altogether.
  • The child inherits two copies of chromosome 15 from the mother, but no chromosome 15 from the father.
  • The father’s genes on chromosome 15 contain an error or defect.

Prader-Willi Syndrome Symptoms and Effects

Signs or symptoms of Prader-Willi syndrome in early infancy to childhood might include:

  • Difficulty with feeding.
  • Distinct facial features.
  • Lack of eye focus.
  • Poor muscle tone.
  • Poor responsiveness.

Prader-Willi syndrome symptoms in childhood might include:

  • Behavioral problems.
  • Crossed eyes (also known as strabismus).
  • Delays in milestones.
  • Difficulty with physical coordination.
  • Excessive sleeping or sleep disorders.
  • Excessive weight gain, overeating or obesity.
  • Extreme flexibility.
  • Infertility and sexual underdevelopment.
  • Learning disabilities.
  • Scoliosis.
  • Short stature.
  • Skin picking and scarring.
  • Speech delay.

Prader-Willi Syndrome Diagnosis and Treatment

At birth or during infancy, a health care provider might suspect Prader-Willi syndrome based on a baby’s symptoms. If your child shows Prader-Willi symptoms, a blood test can help to confirm a Prader-Willi syndrome diagnosis.

Kids who have Prader-Willi syndrome often require care throughout their lives. Treatment options can include:

  • Endocrinologists might recommend human growth hormone (HGH) treatment to help your child increase muscle mass and function. HGH can also help children grow taller and stronger.
  • In some cases, sex hormone treatment can help improve physical development during puberty.
  • Psychotropic medicines can help control compulsive behaviors, if behavioral management techniques aren’t enough.

Kids who have Prader-Willi syndrome often deal with intense food cravings. For many families, it’s easier to help children who have the condition control weight by developing healthy eating habits early on. Nutritionists can create custom nutrition plans and recommend specific ways to manage appetite challenges.

Many kids who have Prader-Willi syndrome experience the following issues with emotions and behavior:

  • Anxiety.
  • Emotional outbursts.
  • Mood changes.
  • Obsessive or compulsive behaviors.
  • Stubbornness.

To help manage these behavioral issues, daily routines, firm rules and positive rewards can help.

Because many children who have Prader-Willi syndrome experience motor delays, physical therapy and occupational therapy can help develop, strengthen and refine physical abilities.

If your child experiences delays in speech, speech and language therapy might help.


Integrated Care

Children who have disabilities or complex conditions such as Prader-Willi syndrome require special care to manage their health challenges.

When you come to Gillette Children’s, your child’s integrated care program is organized around the complications linked to Prader-Willi syndrome, including issues with food, growth and bone health.

In our family-centered environment, you and your child will work with leading experts in endocrinology, nutrition and feeding. Your child might also receive care from specialists in the following areas: