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Prader-Willi Syndrome


Prader-Willi Syndrome is a rare genetic condition that may cause a variety of problems which include a constant feeling of hunger, decreased muscle tone, learning difficulties, sexual immaturity, behavioural issues, and short stature.


All characteristic features of a child are usually influenced by the genes inherited from the parents. Genes are usually found in pairs, one copy from the father (paternal gene) and one from the mother (maternal gene). Prader-Willi syndrome results in any of the following conditions:

  • A paternal gene on chromosome 15 is missing.

  • Two copies of a maternal gene are inherited instead of one from the father and one from the mother.

  • There is a defect in a paternal gene on chromosome 15.


This genetic abnormality causes a disruption in the normal functioning of the hypothalamus, a part of the brain that controls feelings of hunger and thirst and triggers the production and secretion of hormones responsible for growth and development.


Raising a child with Prader-Willi syndrome is challenging due to the related behavioural problems and complications that can have a negative impact on the family. Reaching out to others in a similar situation may be helpful and your doctor can put you in touch with local support groups. Organisations such as the Prader-Willi Syndrome Association of Australia can also be of service to you in this regard.

Our Locations

Taylor Medical Centre

First Floor, Suite 10A

40 Annerley Rd

Wooloongabba Qld 4102


Medici Medical Centre

15 Scott St

(Cnr Scott & Curzon St)

Level 1, Suite 105

Toowoomba, Qld 4350


Children with Prader-Willi syndrome may exhibit the following features:

  • Decreased muscle tone: Is a primary sign during infancy. The child often feels like a rag doll when carried.

  • Unique facial features may include almond-shaped eyes, narrowed temple distance, thin upper lip and a downward turned mouth.

  • Failure to thrive in infancy: This is due to poor sucking reflex as a result of decreased muscle tone.

  • Strabismus: The eyes may not move together with wandering of one eye.

  • Myopia:  Near-sightedness may be present.

  • Poor response to stimulus: The child may seem lethargic and have difficulty waking up.

  • Food cravings: The child will seem constantly hungry even after consuming large quantities of food and usually gains weight rapidly.

  • Underdeveloped sexual features: There may be little to no production of sex hormones resulting in poorly developed sex organs, delayed secondary sexual characteristics and infertility.

  • Short stature: Adults with Prader-Willi syndrome are usually shorter than their parents.

  • Intellectual disability: Problem solving, learning, and thinking abilities are impaired.

  • Delayed motor development: Children are slower at reaching developmental milestones such as sitting, standing, and walking.

  • Speech problems: Children may start speaking late and may have difficulty with articulation even in adulthood.

  • Behavioural issues: Children are likely to throw tantrums when denied food and may be stubborn, angry, and manipulative.

  • Scoliosis: Quite a few children with this condition will develop an abnormal curvature of the spine.

  • Hormonal imbalances: This may be the result of endocrinal abnormalities due to the condition.

  • Light complexion: Light hair and skin may be present compared to other members of the family.

  • Increased pain threshold: This makes it difficult to identify injury or disease.

  • Problems regulating body temperature: This is apparent in conditions such as fever and inability to tolerate hot or cold weather.


A diagnosis of Prader-Willi syndrome is confirmed by a blood test to evaluate for any genetic abnormality. Your doctor may order blood tests based on the signs and symptoms exhibited by your child.


If untreated Prader-Willi syndrome can lead to obesity, hypogonadism, and other complications related to conditions such as type 2 diabetes, heart disease, sleep disorders, liver disease, joint pain, osteoporosis, sterility, binge eating, and significant behavioural issues.

Treatment Options

Treatment options include:

  • Adequate nutrition in infancy: Your doctor may recommend special feeding techniques and formulas to help the growth and development of your child.

  • Healthy diet in children and adults: Strict adherence to a meal plan to avoid overeating that can result in obesity and its complications.

  • Human growth hormone therapy: This therapy increases muscle mass and reduces body fat. A paediatric endocrinologist can determine the necessity of this therapy for your child.

  • Sex hormone treatment: This treatment is recommended in cases of hypogonadism.

  • Sleep disorder treatment: Various treatment options are available to improve sleep patterns and eliminate daytime sleepiness.

  • Physiotherapy: This therapy can help in motor development of the child.

  • Speech therapy: This therapy can be used to improve verbal skills.

  • Occupational therapy: This therapy is used to develop age-appropriate behaviours and social skills.

  • Mental healthcare: This therapy can aid in psychological wellbeing.


Due to the genetic cause of Prader-Willi syndrome it cannot be cured. However, associated symptoms and problems can be appropriately managed with timely treatment Though people with this condition cannot be fully independent, they can certainly improve their quality of life through proper diet restriction and participation in various activities.


Significant research has been done in the treatment of Prader-Willi syndrome. Some studies include.

  • SB, Cassidy; S, Schwartz; JL, Miller; DJ, Driscoll. Prader-Willi syndrome. Genet Med. 2012 Jan;14(1):10-26.

  • S, Pangkanon. Molecular diagnosis of Prader-Willi syndrome. J Med Assoc Thai. 2003 Aug;86 Suppl 3:S510-6.


Have questions?

Check our FAQ section, and if you still have questions or concerns we suggest you take your child to visit their GP, who can refer to us if needed.

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