For Professionals: Physicians & Nurses

Prader-Willi syndrome is a very complex syndrome encompassing a variety of potential medical concerns. It is important for medical professionals to be aware of these issues when treating a patient with PWS. Below we highlight areas of concern which either present unique challenges for PWS or may not present in a typical manner. As with any syndrome the presentation and severity of symptoms will vary by individual; parents are the best source of information for the individual’s specific history.

In addition to the information provided below, medical professionals may contact PWCF at 310-372-5053 or PWSA-USA at 800-926-4797 to seek advice for their patients. We can connect you with doctors from PWSA’s Medical Advisory Board to assist you with the appropriate care for your patient.

What Parents Want Professionals to Know When Giving a PWS Diagnosis

PWS Brief Overview Training Video

Some individuals who have Prader-Willi syndrome may have a reduced ability to fight off infection or illness because of Central Adrenal Insufficiency. If your patient takes an exceptionally long time to recover from illness you may want to consider testing for Central Adrenal Insufficiency. For more information please read Central Adrenal Insufficiency Cortisol Levels in PWS support changes in Routine Care, CAI – Adrenal Insufficiency Rebuttal – 2010, Central Adrenal Insufficiency – Normal Cortisol Response, and Central Adrenal Insufficiency – Relationship Between CAI and Sleep-Related Breathing Disorders.

Unfortunately some patients with Prader-Willi syndrome will die due to complications of the syndrome. Typically death is a result of complications due to morbid obesity, however too little is known about causes of death. While it is a delicate subject, the knowledge that can be gained makes it necessary to discuss the topic of autopsy and tissue donation with the next of kin. Autopsy guidelines are available in Autopsy of the Brain & Tissues and Autopsy on GI Death.

“Fluid retention is usually noted first as swelling of the lower legs. In PWS this is a valuable warning sign that poor weight control is affecting the person’s health. Fluid retention in persons with PWS is usually a sign of a decreased ability to breathe adequately due to excessive weight (“obesity hypoventilation”). With excessive weight, breathing abnormalities first develop during sleep and can be present silently for years without any other signs that something is amiss.” Read the full article here: Fluid Retention – Oedema

While there is no cure or treatment for Prader-Willi syndrome, growth hormone has tremendous benefits for both children and adults. Beginning growth hormone therapy as soon as possible should be considered standard protocol. Early use has been shown to change the penotype of the syndrome and improve IQ; other benefits include increasing lean muscle mass, and improving endurance, among others. For additional information please read the following:

Growth Hormone – Across the Life Span, Efficacy & Safety of Long-term

Growth Hormone – Effective & Safe Long-term Summary 2010

Effects of Growth Hormone Treatment in Children with PWS

Head Circumference and IGF-1 levels with Growth Hormone Therapy

Growth Hormone Improves Mobility & Body Composition

Growth Hormone Treatment of Adults with Prader-Willi Syndrome

Summary of FDA Approval of Growth Hormone

Evaluation and Treatment of Adult Growth Hormone Deficiency: An Endocrine Society Clinical Practice Guideline

Growth Hormone for Adults with Prader-Willi Syndrome

We also recommend PWSA’s Growth Hormone Booklet

Inpatient procedures or hospitalization can present unique challenges for the patient with Prader-Willi syndrome both for crisis situations and routine treatment. For example, it is crucial that all staff be aware of the need for strict food control and not allow the patient extra food or food items not on their approved diet plan. Please read Inpatient Crisis Intervention for patients with PWS and Inpatient Medical Alert.

Hyperphagia is a hallmark characteristic of Prader-Willi syndrome and a patient’s success often hinges on proper food control from ALL caregivers. The insatiable appetite combined with a reduced metabolism can lead to rapid weight gain and obesity in a very short time if ALL food is not strictly controlled by the patient’s parents or caregivers. Please read Food Security Basic Concepts and Eating Themselves to Death.

For further reading here is the Abstract Book from the 2012 Hyperphagia conference.

Hypoventilation in Prader-Willi syndrome typically presents itself with sustained hypoxia which is not typical of non-PWS patients. Please read the recommendations for treating hypoventilation in Prader-Willi syndrome: Clinical Presentation of Obesity Hypoventilation and Right Heart Failure in PWS

There is an increased incidence of scoliosis in individuals who have Prader-Willi syndrome, therefore annual screenings (including an x-ray) should continue throughout childhood and adolescence. Often the curve does not appear as severe on physical exam and the severity is only discovered upon review of an x-ray which is why an annual x-ray is recommended even in the absence of physical findings. Adults should continue to be screened as diagnosis may have been missed earlier in life or scoliosis may have developed degeneratively. For more detailed information about monitoring for and managing scoliosis, please read the following:

Guidelines on Scoliosis Monitoring and Treatment

Comparison of Scoliosis Treatment in PWS

Scoliosis – Complications of Surgery 2008

Scoliosis in PWS Pediatric Patients

Growth Hormone Effects on Scoliosis

Scoliosis and PWS – PWSA Survey

Scoliosis & PWS

Several sleep disorders including obstructive apnea, central apnea, and narcolepsy may be at increased risk in individuals with Prader-Willi syndrome. Please read the following for more information:

Central Adrenal Insufficiency – Relationship Between CAI and Sleep-Related Breathing Disorders

Sleep Journal Article on Narcolepsy in PWS

Respiratory Problems in PWS

Recommendations for Evaluation of Breathing Abnormalities Associated with Sleep in PWS

The propensity toward obesity can only be overcome with proper caloric intake and regular exercise. Typical weight loss medications and procedures have not been successful in patients with Prader-Willi syndrome. Please read the following:

Overview of Food & Behavior Management

Brochure – Overview of Food Behavior

Regulation of Weight in Prader-Willi Syndrome – Theoretical and Practical Considerations

Success of Low Carb, High Protein Diet

Calorie Serving Guide for Infants and Toddlers

Need To Know Nutrition for Children with PWS

University of Queensland Brochure: Exercise and Physical Activity for children with PWS

PWSA-USA also has several publications focusing on nutritional guidelines for PWS.

A blood test can confirm a diagnosis in most cases. If you suspect your patient has Prader-Willi syndrome print the Diagnostic Criteria Sheet and mark the traits observed or reported by the parents or review the diagnostic criteria from PWSA-USA. Ideally you should start with a methylation test which detects approximately 99% of PWS cases. If the methylation test is positive further testing via the FISH test or a PCR test will be needed to determine the sub-type; deletion or UPD respectively. There have been numerous instances when a negative FISH test (which only detects deletion) results in a family being told their child does not have PWS and only later (sometimes much later) to discover via a methylation or PCR test that their child has the UPD sub-type. Referral to a geneticist is recommended.

When delivering a diagnosis of PWS to a parent we suggest providing them with material they can read later as only a small amount of what you tell them initially will be remembered once they leave your office. Also, let the family know that while it is a complicated syndrome, it is manageable and that organizations like Prader-Willi California Foundation are available to help. Particularly for patients diagnosed in infancy, their future, thanks to early intervention and early use of growth hormone, is much brighter than prior generations. You can direct families to our section for parents which contains lots of valuable information for them or to our newly diagnosed page. PWSA-USA has also prepared some tips on Giving Difficult News to a Family.

Individuals with Prader-Willi syndrome, because of their decreased metabolism, do not typically respond to medication, including anesthetic agents, in the same way as others therefore caution should be taken for patients who need surgery. Please read Issues Affecting Prader Willi Syndrome and Anesthesia, Anesthesia – Guidelines for Postoperative MonitoringAnesthesia and PWS – Preliminary Experience with Regional Anesthesia, and Anesthesia – Concerns for Patients.

People who have Prader-Willi syndrome have decreased, yet thick and sticky saliva which makes them prone to cavities and increased tooth wear. Good oral hygiene and regular visits to the dentist are key in maintaining healthy teeth. Read the Dental tips & tricks sheet for more information.

Numerous gastrointestinal issues can impact people with Prader-Willi syndrome and can become life-threatening if not properly addressed. Increased pain threshold and a reduced or absent vomit reflex can complicate diagnosis and treatment. Of particular concern is a the acute onset of severe stomach pain as this may signal a serious medical condition. Please see the following for important information:


Life Saving GI Evaluation Algorithm Chart

Acute Gastrointestinal Episodes Can be Life-Threatening

Medical Alert – Constipation in Individuals with PWS

Gastroparesis & Bowel Issues

Gastric Rupture & Necrosis in PWS (Journal Article)

A Comprehensive Overview of GI Issues in PWS

Medical Alert – Risk of Stomach Necrosis and Rupture

People with Prader-Willi syndrome tend to have a higher than normal pain threshold, therefore objective evidence (such as an x-ray, sonogram, etc.) should be obtained. There have been reports of individuals having broken bones but because of the absence of reported pain were only discovered once x-rayed.

Both males and females with Prader-Willi syndrome experience hypogonadism, disrupted function of sex hormones and decreased fertility/infertility. Additional Reading: Hypogonadism in Females, Primary Testicular Dysfunction, and Documented cases of fertility.

Many individuals with Prader-Willi syndrome lack the vomit reflex and will not throw up when ill. Vomiting therefore may be a sign of very serious illness. It is important to note though that some individuals with PWS do vomit, however medical staff should err on the side of caution.

Some individuals who have Prader-Willi syndrome have psychiatric disorders, have the inability to cope with stress which then manifests itself in psychiatric symptoms, or may just have generalized depression or anxiety related to the recognition of their diagnosis of PWS and therefore may benefit from therapy and or psychotropic medication. For more information please read:

PWS – A Primer for Psychiatrists

Psychotropic Medication Tip Sheet

Effects of Topiramate in Adults with PWS – 2004 AJMR

Psychiatric Alert for PWS


Psychology – Cognitive Profile

Psychiatry – Help for the Child

The PWS Pesonality – What is Within Normal Limits

Behavioral Difference between Patients with PWS between genetic sub-types

Some people with Prader-Willi syndrome skin-pick and this behavior can impede healing after injury or surgery. Please read this Skin Picking article from Dr. Gourash of the Pittsburgh Partnership.

People with Prader-Willi syndrome typically have difficulty maintaining appropriate body temperature. Often the normal temperature of someone with Prader-Willi syndrome runs lower than average. It is important that medical staff know this because a normal temperature of 98.6 may in fact mean a slight fever for the individual with PWS, or what appears to be a slight fever may in fact be a sign of a more serious illness. Conversely, some individuals may not present with a fever even when ill, therefore the absence of a fever in the individual with PWS should not necessarily be taken as evidence that there is no illness/infection.

Water intoxication can, of course, happen to anyone who consumes an excessive amount of water, however it may be of particular risk to an individual with Prader-Willi syndrome if they require a particularly high level of supervision not just around food but around water. Please read PWSA’s Water Intoxication Alert.

Make Connections

PWCF maintains online and in-person Support Groups for parents and professionals.

PWSA (USA) maintains several Facebook support groups.