Prader-Willi syndrome

Prader-Willi syndrome (PWS) is a rare genetic disorder. It is the most common cause of obesity caused by a genetic syndrome and is primarily characterised by:

  • neonatal hypotonia
  • sexual infancy: hypogonadism
  • obesity
    • there usually morbid obesity resulting from hyperphagia is amplified by decreased energy expenditure and reduced physical activity.
    • the hyperphagia has often been proven refractory to all psychopharmacological interventions
  • mental retardation
  • short stature



It is thought to result from an alteration (deletion or partial deletion) in the molecular composition of a critical region of chromosome 15 (q11-13)

Radiographic features


Reported radiographically detectable features in childhood include 2:

  • abnormalities of the calvarium and sella turcica
  • small hands and feet with thin cortices and over-tubulated bones, and unequal extremities
  • coxa valga
  • scoliosis
  • advanced dental caries

Sometimes later consequences such as early degenerative changes (non-specific) from morbid obesity may be seen.

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Article information

rID: 6981
System: Paediatrics
Tag: cases
Synonyms or Alternate Spellings:
  • Prader-Willi syndrome (PWS)
  • Prader Willi syndrome

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Cases and figures

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    Case 1: morbid obesity
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