This guide is intended as an overview
of the syndrome across all ages. It goes through the first and second
stages of the syndrome, details more of the PWS characteristics and has
some suggested management strategies.
Prader-Willi Syndrome (PWS) is a complex medical condition that affects boys and girls equally and continues to affect them throughout their lives. People with Prader-Willi Syndrome have an obsession with food and eating (from about age 2), poor muscle tone and balance, learning difficulties, lack of normal sexual development, emotional instability and lack of maturity. It has been estimated that about 1 in 15,000 people from all races are born with PWS - it is not inherited in 99% of cases. The name of the syndrome is derived from the names of the doctors who first described the disorder in 1956.
Every child is an individual and not every person affected by the syndrome will have all of the characteristics. They are also seen in varying degrees. Early diagnosis gives the child a more positive start with early intervention and sensible eating plans. PWS is a genetic disorder and an abnormality of chromosome 15 is seen in the majority of patients. In the past children were diagnosed clinically but now chromosome and/or DNA testing can be arranged through The Royal Children's Hospital, Melbourne.
There are two distinct clinical stages to the syndrome. The first stage occurs from birth through to the ages of two to four. Babies are born with extremely low muscle tone, which means they will need to be fed initially by gavage or special teats. They also sleep a lot, so it is important that when awake they receive visual stimulation and interaction. The baby's position needs to be changed from sleep to sleep so that they are not always Iaying on one side.
The low muscle tone means that it will take longer than normal to reach developmental milestones. There is a wide range for any child's development but most children with PWS will reach these particular milestones as follows:
Smiling - 4 months
Independent sitting - 13 months
Single words - 21 months
Walking - 28 months
Sentences - 3.6 years
The importance of early intervention in areas such as physiotherapy, speech therapy and occupational therapy cannot be over emphasised. These services are available free through the Department of Human Services (DHS) for families of special needs children.
The second stage of the syndrome usually occurs from around 2 years, or in some cases later. Although diet remains the same, weight will start to balloon. This may be accompanied by a compulsion to eat and an obsession with food. If nothing is done to manage diet, or restrict food, then serious weight gain that can result in life threatening obesity will occur in 95% of cases. Early intervention means this outcome is no longer inevitable.
Changes in behaviour may also become evident over time with tantrums, stubbornness and mood swings occurring. When the weight gain starts a special diet plan needs to be formulated in consultation with a dietician, so that growth needs can be taken into account. Exercise is an essential ingredient to help fight the calories.
People with PWS have a range of learning disabilities regardless of their IQ, which is often in the mild to borderline range. However poor social and emotional skills inhibit the person performing up to that IQ. Rigid behaviour and tantrums are part of the syndrome and not a result of over-indulgent parenting. All staff should agree to the same method of dealing with the child. Build supported change and choice into lessons and activities.
Specific weaknesses in maths and writing are common, but reading and art skills are considered strengths. Short-term auditory memory is often weak, but longterm memory is again a strength. Visual aids and cues to learning should therefore be used as much as possible. Make sure ALL school staff are aware of the need for dietary control. Like all children, those with PWS perform better if their efforts are praised and acknowledged, and they will persevere at tasks if they are well motivated.
Most children with PWS go to local kindergarten and primary school. Some may go through high school or attend a special school to learn life skills. People with PWS often work in supported employment. Independent living is rarely achieved.
Children with PWS have a range of learning disabilities regardless of their IQ, which is often in the mild to borderline range of intellectual disability. Cognitive dysfunction is nearly always present. Specific weakness maths and writing are common, but reading and art skills are considered strengths. Most children with PWS go to local kindergarten and primary school. Some may go through high school or attend a special school to learn life skills. Independent living is rarely achieved.
It is important that the child's eyesight, hearing and teeth are checked. There may well be nothing wrong but if there is it is better to do something about it earlier than later. Children with PWS rarely vomit, and some have a high pain threshold - which means that they can be very ill but they won't complain as other children would.
Other characteristics include (although not all characteristics occur in every case):
Excessive sleepiness or sleep apnoea
Small hands and feet
Strabismus (squint) and myopia (short sightedness)
Sticky, foamy saliva
Lack of gag reflex
Inaccurate body temperature regulation
Prenatally, foetal movement is decreased
Scoliosis (curvature of the spine) or Kyphosis
Speech and articulation defects
Adverse reaction to drugs and anaesthetics
Puberty may start early, but full sexual development is frequently
delayed or may be reached at a later stage in life. Periods in girls are frequently absent or irregular.
People with PWS have particular behavioural characteristics that anyone who has dealings with them needs to understand. Some of these are:
Rigid thought patterns: There is a strong need for routine, sameness and consistency in their environment.
Perserverative thinking: When stuck on an issue, there is no point in reasoning with them - try to distract them to another topic or defer the discussion to some other time.
Poor emotional control: Evidenced by tantrums, yelling, swearing, aggression, destruction, and self injury. This can be brought on by any combination of stresses. It takes time for them to recover control and the incident is often followed by sadness, remorse and guilt - reassurance is important after the event. "Time out" is often a successful strategy.
Diet restrictions: People with PWS, from the onset of insatiable appetite, will never have control over their craving. It is not a matter of self control; their brain just doesn't register that they have had enough to eat. They require considerably fewer calories - 30 to 50% less than the average person - so they should never be put in a situation where they are left alone with food. Parents' guidelines should be followed and punishment for taking food is not appropriate.
Excessive sleepiness: People with PWS can tire more easily and may fall asleep during the day. Morning is typically their optimal learning time.
Scratching and skin picking: Often seen in individuals with PWS, if the behaviour increases then consider what may be adding additional stress in their environment. Combined with the higher pain threshold, these behaviours can result in tissue damage if not controlled.
There is a lot of research being carried out on various aspects of PWS but to date there is no cure. Through increased knowledge we can help all people with this condition to live a fuller life despite their limitations.
Children with PWS are generally happy. delightful people and they are very easy to love.
There are some terrific resources available on other PWS and Government Sites - we have included some links here.
Policy Statement: Adults With Prader-Willi Syndrome and Decisions Regarding Least Restrictive Environment and the Right To Eat: This has been formulated by the Prader-Willi Syndrome Association of USA.
Medical Information for PWS: A list every parent, and their doctor, should have.
Behaviour Management: This is a terrific 12 page document from the PWSA (UK) - Click here to view or download
Educating the Child with Prader-Willi Syndrome:
CDDH Victoria improve health outcomes for people with developmental disabilities through a range of educational, research and clinical activities
Find a Disability Employment Service:
DHS Disability Services: Programs, Publications, Useful Services, Links to other Services
Disability Online: Information for people with a disability, their families and carers
Planning for the Future: People with disability
Australian Government Disability Site