Approved by the Clinical and Scientific Advisory Board of the International Prader-Willi Syndrome Organisation (IPWSO)

January 2018

 

Prader-Willi syndrome (PWS) is a complex genetic disorder with many manifestations and potential medical and psychiatric complications. Genetic testing is available to confirm the diagnosis. Because of cognitive dysfunction and behavioral problems, adults with PWS might have difficulty describing how they feel, and their capacity to make judgments about their condition may be impaired. Therefore, a careful medical history taken from the family/caregivers and relevant examinations are important.  As a result of improved knowledge about PWS in the past few decades, many affected adults are living to old age, particularly when rigorously supervised, energy-restricted diet and prevention and/or treatment of comorbidities occurs.

 

The following potential complications make it valuable for adults with PWS to have an annual general physician evaluation. IPWSO recognizes that access to health services and to specialists may vary considerably due to factors that include poor transport, limited financial resources, or great distances. This document summarizes the main health needs that are recommended in the context of available resources.

 

Most Common and/or Serious Medical Findings

 

•  Small muscle mass and hypotonia - often associated with little physical activity and therefore low calorie needs. Even if weight is normal for height, the fat mass is high.

• Uncontrollably strong biologically determined drive to eat - leads to massively increased fat mass if food is not controlled externally through constant lifelong supervision and support concerning access to food.

• Severe obesity - complications of which include type II diabetes, hypertension, respiratory and cardiac insufficiency, sleep apnea, hypercholesterolemia, skin changes and ulcers, and joint abnormalities.

• Hormonal insufficiencies such as hypothyroidism, growth hormone deficiency and often hypogonadism with attendant complications (e.g., osteoporosis).

• Gastrointestinal problems - chronic constipation, reflux, choking, and the risk of catastrophic cascade of gastric distention, necrosis and deadly rupture.

• Many are unable to vomit, and pain threshold is high.

• Skin picking - when severe can lead to scarring and potentially serious infections, including of surgical incisions. For many it is provoked by stress or idleness.

• Rectal picking - when severe can lead to chronic anemia and misdiagnosis as colitis or inflammatory bowel disease (sometimes starts because of constipation)

• Spinal deformities - scoliosis, kyphosis or kyphoscoliosis, present in up to 80%.

• Intellectual disability and behavioral disorders - can be mild but are often severe, requiring constant personal assistance and support (as for food control)

• Psychosis and/or mood disorders - can arise unexpectedly, requiring psychiatric evaluation and medication. Sudden changes of behavior or loss of appetite may indicate physical or psychiatric illness.

• Respiratory problems - responsible for a high proportion of deaths in PWS.

 

Additional Issues

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• Temperature regulation abnormalities - sometimes causes hyperthermia, hypothermia, and lack of febrile response even with severe infections.

•  Communication difficulties - causes inability to express feeling ill and/or in pain·       High pain threshold - increases the risk

• underappreciating the presenting symptoms and overlooking several diseases and fractures. X-ray and abdominal scans must be considered even if symptoms observed are not severe.

•  Gastroparesis and gastric necrosis - a distended stomach can be seen both after overeating and with other conditions, including constipation. Gastric necrosis can occur with a distended stomach, and symptoms can be few. Vomiting and loss of appetite can be signs of life threatening intra-abdominal disease. Medical evaluation and treatment can be lifesaving. 

 

Concerning Medication

 

Many patients with PWS are treated with several daily medications, the necessity for each of which should be periodically re-evaluated. Due to their small lean body mass and, often, increased sensitivity to drugs, a low starting dose is suggested, especially for psychotropic drugs and antihistamines. Respiratory complications can result from the use of standard doses of benzodiazepines.

 

Psychiatry

 

It is valuable to have people with PWS who are on medication for psychiatric or behavioral problems, even those who are well controlled, be seen by a psychiatrist periodically.

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General remarks

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This document is designed to address the medical problems encountered in adults with PWS in an effort to reduce serious medical problems and improve quality of life. A separate IPWSO document addresses evaluations during regular medical visits.

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PWS is due to absence of genetic information on chromosome 15 due to one of three genetic changes (deletion at chromosome 15q11.2-q13; uniparental disomy 15; an imprinting defect on chromosome 15). It is very strongly recommended that the diagnosis be confirmed through genetic testing. A DNA methylation analysis confirms the diagnosis in >99% of cases. IPWSO can be of assistance in identifying sources of testing. Some other conditions can overlap in signs and symptoms with PWS.

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Much of the medical care needed in PWS is not expensive or difficult to obtain in most countries and is not different from the medical care of other patients with similar findings.

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Please also see medical and other information, most of which is written for a lay audience, on the International Prader-Willi Syndrome Organization (IPWSO) website that includes information about family support organizations in over 100 countries:

http://www.ipwso.org

 

A source of detailed information about PWS on the internet is in GeneReviews: