Introduction

There have been many research trials, which show clear benefits for children living with PWS. These include:

• Increased growth (height)
• Improved tolerance for exercise
• Improved bone health
• Improved motor development, muscle strength, tone and body composition (i.e. more muscle mass and less fat mass)
• Improved respiratory function.

Should every child with PWS be given GH treatment?

GH treatment should be considered for every child with PWS. The PBS will subsidise treatment for a child living with PWS if their doctor recommends it and has confirmed it is safe to go ahead. GH treatment is not compulsory, and some families decide not to have GH for their child, which is also OK.

There are some medical reasons why treatment with GH might not be started:

• A significant illness in addition to the syndrome
• Severe obesity
• Severe breathing problems
• Untreated central and/or obstructive sleep apnoea[1]
• Uncontrolled diabetes

Side effects of growth hormone treatment

Growth hormone treatment has been used for children with growth problems since the 1960’s and recombinant (laboratory manufactured GH) has been available since 1985. GH has been used to treat people living with PWS since the 1990s.

Children who have been treated with GH for any reason has shown very few reported side effects.

For anyone treated with GH for any reason:

• There is a side effect called benign intracranial hypertension which causes very severe headaches. This is rare and goes away if GH is stopped.
• Follow-up of people who have been treated with GH in the past does not suggest that there is an increased risk of other illnesses later on, but these studies are continuing.

For children living with PWS treated with GH:

• When the first studies of GH treatment in PWS were started there were reports of a few children who died in the time around starting GH. A clear link with the GH treatment was not proved, but it has been shown that GH changes the airway for some children with PWS and could potentially make obstructive sleep apnoea worse. This is the reason for the assessments that are done before starting GH and why individuals are now closely monitored whilst on GH, especially when it is newly started. The risk is greater for children who are obese.
• Diabetes can become more difficult to control if GH is started.
• 30-40% of children living with PWS develop scoliosis (which can vary from very minor to severe). Recent studies have not shown that there is an increased risk of this happening with GH treatment and a 2019 study hypothesised that treatment may lead to a lower spine curvature in children. However, scoliosis may be a reason why GH is not started.

At what age should growth hormone treatment start?

The first studies of GH in children living with PWS looked at older children, but more recent research has shown benefit in younger children, and there have been studies looking at GH in infants. There is good evidence to support starting GH early in life, before 2 years of age, unless there are medical reasons why this would not be advised.

Assessment and tests before starting GH

Because of the concern that GH may have respiratory effects, it is recommended that a sleep study be performed before GH therapy is started. This test might suggest that treatment is needed before GH can start, (for example removal of tonsils or adenoids, starting overnight respiratory support).

Some specialists check for growth hormone deficiency before starting GH (either with IGF 1[2] testing or a stimulation test), but children living with PWS in Australia do not have to confirm GH deficiency to start GH treatment. Note: the rules are slightly different for adults.

Before starting GH, your child should have a blood test to check for underactive thyroid (hypothyroidism[3]) as this should be treated before GH can be started. Your specialist will also check your child’s growth level IGF-1to allow monitoring of GH treatment.

Monitoring treatment

Whilst receiving GH treatment, your child should be monitored every 3-6 months to ensure that the treatment is both safe and effective.

They will have regular blood tests and medical assessment which can include:

• Height and weight measurement and assessment of body composition.
• Blood tests about once a year, including thyroid function (looking for hypothyroidism) and IGF 1 (which is a marker of GH levels in the body and a way of monitoring the dose of GH) and markers for diabetes.
• Assessment of breathing and sleeping patterns. A repeat sleep study should be considered for all children with PWS within the first 3-6 months after starting on GH and at regular intervals thereafter.
• Checks for scoliosis.
• Assessment for any other side effects of GH treatment.

Weight management during GH treatment

GH treatment does not change the problems of increased appetite in PWS and is not a solution to weight gain. During the first few years of life, it is important to get your child into good habits with their diet and set firm boundaries around their eating habits. Children with PWS need less calories; approximately 60—80% compared to children without PWS. Regular exercise is helpful and GH treatment can help by improving muscle strength.

Length of time for treatment

Unless there are unexpected complications or reasons why GH is no longer appropriate, GH treatment should continue until your child has stopped growing.

Further reading regarding research into the benefits and risks of growth hormone treatment for people living with PWS can be found at https://www.fpwr.org/the-importance-of-growth-hormone-therapy-for-pws#considerations

Approval by the PBS

Subsidised GH treatment for all children living with PWS in Australia was approved by the Commonwealth Pharmaceutical Benefits Scheme (PBS) in 2009. More recently, subsidised GH for adults was approved under certain conditions (see the Growth hormone for adults living with PWS page). Details about the PBS GH (Somatropin) Program can be found at Pharmaceutical Benefits Scheme (PBS) | Growth Hormone Program

To access growth hormone treatment for your child, please see your treating GP or endocrinologist.

Thank you …

to PWSA UK for the original source material, including contributions from:

• Dr Ruth Krone MD FRCPCH—Consultant in Paediatric Endocrinology and Diabetes, Birmingham Children’s Hospital NHS Foundation Trust.
• Dr Nicola Bridges—Consultant Paediatric Endocrinologist, Chelsea and Westminster Hospital, London.
• Prof Tim Barrett— Professor of Paediatrics, Honorary Consultant in Paediatric Endocrinology and Diabetes, and Program Director for the Wellcome Trust Clinical Research Facility at Birmingham Children’s Hospital.
• Dr Kanumakala Shankar— Consultant Paediatric Endocrinologist, Royal Alexandra Hospital, Brighton.

[1] Central and/or obstructive sleep apnoea – occurs when the brain sends the signal to the muscles and the muscles make an effort to take a breath, but they are unsuccessful because the airway becomes obstructed and prevents an adequate flow of air.

[2] IGF-1 – a hormone produced by the body in response to GH. Blood levels of IGF1 are used as a way of monitoring the dose of GH.

[3] Hypothyroidism – (underactive thyroid gland) is the term used to describe a condition in which there is a reduced level of thyroid hormone (thyroxine) in the body. This can cause various symptoms, the most common being tiredness, weight gain, constipation, aches, dry skin, lifeless hair and feeling cold. Treatment is usually by taking a tablet each day to replace the missing thyroxine. Treatment usually works well, and symptoms usually go. Around a third of children with PWS have this condition, but it is less common in adults with PWS.