Prada-Willi Syndrome - Sydney Cognitive Development Centre

WHAT IS PRADER-WILLI SYNDROME?
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 (some 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.

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 Children's
Hospitals around Australia.

EARLY DEVELOPMENT
Babies are born with extremely low muscle tone,
which means they will need assistance feeding.
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 Iying 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

Early intervention in areas such as physiotherapy,
speech therapy and occupational therapy is very
important.

From approximately age 2 (or possibly 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.

COGNITIVE PROFILE & LEARNING DIFFICULTIES
People with PWS have a range of learning
disabilities regardless of their IQ, which is often in
the mild to borderline range. Cognitive dysfunction
is nearly always present. Poor social and emotional
skills often inhibit the person performing up to
potential. Rigid behaviour and tantrums are a
common part of the syndrome.

Specific weaknesses in maths and writing are
common, but reading and art skills are considered
strengths. Short-term auditory memory is often
weak, but long-term memory is again a strength.
Visual aids and cues to learning should therefore be
used as much as possible. 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.

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.

OTHER CHARACTERISTICS
Other characteristics include (although not all
characteristics occur in every case):
• Skin picking
• Excessive sleepiness or sleep apnoea
• Short stature
• Small hands and feet
• Strabismus (squint) and myopia (short
sightedness)
• Sticky, foamy saliva
• Lack of gag reflex
• Inaccurate body temperature regulation
• 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.