Prader-Willi syndrome

Prader-Willi syndrome is a rare genetic disorder. It is the most common cause of obesity caused by a genetic syndrome.

Prader-Willi syndrome is primarily characterized by:

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

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

A very similar condition (referred to as Prader-Willi phenotype) is also encountered as part of fragile X syndrome 6

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.

Article information

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

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Cases and figures

  • Case 1: morbid obesity
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