What is Prader-Willi syndrome (PWS)?
Prader-Willi syndrome (PWS) is a genetic syndrome that affects one in every 12,000-15,000 people of both sexes and all races and ethnic groups. It is caused by a disorder of chromosome 15.
To learn more about genetics and to better understand how genes cause syndromes, see YourChild: Genetic Syndromes.
What are the features of children with PWS?
Any of these symptoms may show up in your child and can vary from mild to severe:
- Low muscle tone (hypotonia or floppy baby).
- Feeding problems and poor weight gain in infancy.
- Extreme hunger, overeating, obsession with food after infancy.
- Big weight gain between one and six years of age. This leads to serious obesity if no steps are taken to help.
- Distinctive facial features: narrow face, almond shape eyes, small mouth with thin upper lip and down-turned corners.
- Hypogonadism (less than normal sex hormones), leading to incomplete sexual development, undescended testicles, small penis, delayed puberty.
- Developmental delay, including mild to moderate intellectual disability and learning difficulties.
- Infants and children are typically happy and loving and exhibit few behavior problems.
- Older children and adults have problems with behavior regulation, such as difficulties with transitions and unanticipated changes.
- Other behavior problems may include: temper tantrums, violent outbursts, obsessive/compulsive behavior, stealing, lying and being argumentative, rigid, manipulative and possessive.
- Short stature, small hands and feet.
- Fair skin.
- Speech problems.
- Skin picking, which can cause sores.
What causes Prader-Willi syndrome? Is there a test for it?
The syndrome is caused by genetic deletions (missing genetic material) on Chromosome 15. The way it happens is complicated. If you want to know more, visit the links below. Genetic tests for PWS are available. People with the signs and symptoms of PWS should get tested. The types of tests and how they work are reviewed in the following links:
- The Genetics of Prader-Willi Syndrome: An Explanation for the Rest of Us
- Gene Tests-Gene Clinics: Prader-Willi Syndrome has lots of fairly academic information on inheritance, genes, genetic testing, and prenatal testing. You can register for free to get the full review.
- Severe obesity is the major medical problem
- Obesity-related problems—including diabetes, high blood pressure, chronic venous insufficiency (leading to ulcers or sores on legs and feet), cellulitis, and hypoventilation
- Strabismus (crossed eyes) may require surgical correction
- Osteoporosis can occur earlier than usual and can cause fractures
- Sleep disturbances and sleep apnea (also in Spanish: Apnea del sueño)
- Dental problems—including soft tooth enamel, thick saliva, poor oral hygiene, teeth grinding
- Weight management is a major task of parents of kids with PWS. These kids need a balanced, low calorie diet with vitamin and calcium supplements, along with plenty of exercise. You will probably need to restrict access to food by locking your cabinets and refrigerator. No medication or surgical intervention has been found to eliminate the need for strict dieting.
- Check out this book: Red Yellow Green: System for Weight Management, by Karen Balko, RD. “This book will give you calories, cup sizes and visual tips to providing a structured food plan. A 7-day meal plan is included for 800, 1000, 1200 and 1350 calorie plans.” It is available to order from PWA-USA for $25.00. Scroll down the “R’s” on the publication order form.
- Growth hormone is a common medication used in PWS. It increases muscle mass and function, may allow for a higher daily calorie intake, and helps kids grow taller.
- Get the Facts: Growth Hormone Issues in Children and Adults is a 16-page brochure that talks about growth hormone and growth hormone treatment, and some specific conditions, including PWS.
- The brochure, A Comprehensive Team Approach to the Management of PWS is available in English, German, Romanian and Greek. It discusses the use of Growth Hormone to treat PWS. Please note that the pharmaceutical company that produces growth hormone medication funded this brochure.
- Sleep apnea may need to be checked out with a sleep study, and may require treatment. Growth hormone treatment can worsen sleep apnea, according to recent research, so kids on growth hormone should be carefully followed and monitored for problems.
- Sex hormone replacement can lead to more normal physical development in puberty.
- Behavioral management—daily routines, structure, firm rules and limits, and positive rewards work best.
- Psychotropic medications may help with obsessive-compulsive symptoms and mood swings if behavior management alone is not enough.
- Physical and occupational therapy help promote motor development along with growth hormone.
- Speech and language therapy may help with speech delays.
- Early intervention and special education can help your child reach their full potential. Find out everything you need to know about early intervention and special education at YourChild: Developmental Delay.
- YourChild: Genetic Syndromes
- YourChild: Chronic Conditions
- YourChild: Developmental Delay
- YourChild: Siblings of Children with Special Needs
- The University of Michigan Pediatric Endocrinology Program can help with growth disorders lilke Prader-Willi.
- Prader-Willi on Medline Plus has links to helpful information.
- The Prader-Willi Syndrome Association USA website contains tons of useful information, support groups, conferences/activities, free books and pamphlets, and links to other good websites.
- Some Spanish resources.
- The International PWS Organization provides basic information on PWS in very many different languages.
- The Foundation for Prader-Willi Research is a group that promotes research into treatment and finding a cure for PWS. Their site offers information on treatment, new treatment trials, research, and action.
Written and compiled by Kyla Boyse, R.N. and Tarin Gitlin, M.D. Reviewed by Kathy Clark, RN, CS, MSN.
Updated May 2008