Prader-Willi Syndrome

What is Prader-Willi syndrome?

Prader-Willi syndrome (PWS) is the most common known genetic cause of life-threatening obesity in children. Although the cause is complex it results from an abnormality on the 15th chromosome. It occurs in males and females equally and in all races. Prevalence estimates have ranged from 1:8,000 to 1:25,000 with the most likely figure being 1:15,000.

PWS typically causes low muscle tone, short stature if not treated with growth hormone, incomplete sexual development, and a chronic feeling of hunger that, coupled with a metabolism that utilizes drastically fewer calories than normal, can lead to excessive eating and life-threatening obesity. The food compulsion makes constant supervision necessary. Average IQ is 70, but even those with normal IQs almost all have learning issues. Social and motor deficits also exist. At birth the infant typically has low birth weight for gestation, hypotonia (weak muscles), and difficulty sucking due to the hypotonia which can lead to a diagnosis of failure to thrive. The second stage ("thriving too well"), has a typical onset between the ages of two and five, but can be later. The hyperphagia (extreme unsatisfied drive to consume food) lasts throughout the lifetime. Children with PWS have sweet and loving personalities, but this phase is also characterized by increased appetite, weight control issues, and motor development delays along with some behavior problems and unique medical issues.

  • Prader-Willi Syndrome Association is an organization of families and professionals working together to raise awareness, offer support, provide education and advocacy, and promote and fund research to enhance the quality of life of those affected by Prader-Willi syndrome.


Speech accessibility and communication aids enable people who are unable to talk, or to talk clearly. These users may have acquired brain damage, autism, cerebral palsy, Down syndrome, intellectual impairment, or strokes. Many speech recognition systems are unable to recognize the speech of these users because they are based on average speakers. Because of the inconsistency of most impaired speech, speaker dependent systems do not have a high rate of accuracy. Speech recognition should not be the only form of input. In addition, some users with impaired speech may have additional motor skills accessibility problems because of impaired dexterity.

Speech accessibility includes difficulties with language and meaning, and difficulty producing intelligible speech. Language and meaning difficulties can also be related to Cognitive impairment. See the tags list below for related resources.

Reference Books and Resources

There are several excellent books related to speech. See the suggested reading list for general information and detailed reference books for your library.

Speech Resources

Learning and Speaking

Find more resources using the Areas of Focus Speech category search.

Recent and Relevant

Advances in Converting Text to Speech

  • Apple® Accessibility Features Vision built into all Macintosh computers provides adjustable keyboard, an ergonomic mouse, CloseView screen magnification software, Easy Access system software (StickyKeys, SlowKeys, MouseKeys), electronic documentation, key-repeat disable, text-to-speech synthesis and voice recognition (PlainTalk), sticky mouse, and visual alert cues. The VoiceOver spoken English interface for Mac OS X is a fully integrated, built-in screen reader technology providing access to the Macintosh through speech, audible cues, and keyboard navigation.
  • NaturalReader a powerful Text To Speech reader: Listen to PDF files, webpages, e-books, e-textbooks, office documents, and printed books.