What is Prader-Willi syndrome?

Prader-Willi syndrome is a lifelong genetic condition that affects many parts of the body.

Prader-Willi syndrome is caused by a change to a chromosome. This change to chromosome 15 happens by chance and isn’t inherited.

This syndrome is a rare condition, which happens in 1 in 15,000 births.

Signs and symptoms of Prader-Willi syndrome

The signs and symptoms of Prader-Willi syndrome vary.

Physical characteristics
Newborns with Prader-Willi syndrome are typically floppy. They have feeding difficulties because their low muscle tone makes it hard for them to suck. Often these newborns need help from a feeding tube.

Low muscle tone also means that it takes children with Prader-Willi syndrome longer to reach developmental milestones like sitting, crawling and walking.

Other physical signs and symptoms can include:

• failure to thrive in infancy
• short stature
• small hands and feet
• obesity from overeating, which can start at 2-4½ years
• undescended testicles and small genitalia in boys
• irregular or no periods in girls
• high tolerance of pain
• problems regulating body temperature, which means children might not get fevers when they have infections
• inability to vomit
• lighter skin, eyes and hair compared with other family members
• scoliosis
• excessive sleepiness during the day
• breathing issues while sleeping.

Physical signs of Prader-Willi syndrome also include facial features like a narrow bridge of the nose, a high and narrow forehead, a thin upper lip and downturned mouth, almond-shaped eyes and a squint.

Cognitive signs
Most children and teenagers with Prader-Willi syndrome have mild to moderate intellectual disability.

For example, they might have difficulties with:

• maths, reading and writing
• short-term memory
• recognising and interpreting sounds
• organising information, solving problems and planning
• speech and language
• understanding how others are feeling
• understanding what others are saying and knowing how to respond.

Behaviour signs
One of the key characteristics of Prader-Willi syndrome is excessive appetite. This can lead to overeating and obesity. Other behavioural signs might include:

• strong preoccupation with food, which makes it hard for children to concentrate on other things
• unusual behaviour related to food – for example, hoarding food
• high sensitivity to stress, which makes it hard for children to cope with things like changes to routine
• skin picking
• a preference for standing very close to people
• anxiety
• difficulty telling the difference between real things and made-up things
• temper tantrums and aggressive behaviour
• manipulative behaviour.

Medical concerns linked with Prader-Willi syndrome
Children with Prader-Willi syndrome can have medical concerns like:

• rupture of the stomach from overeating
• constipation
• bowel obstruction
• sleep apnoea and other sleep disorders
• type-2 diabetes
• undetected infections or injuries because of their high pain tolerance
• a higher risk of choking because of their inability to vomit
• growth hormone deficiency
• osteoporosis.

Strengths
Children with Prader-Willi syndrome often have strengths in:

• long-term memory and visual memory
• tasks that involve visual-spatial skills, like solving jigsaw puzzles
• decoding letter patterns and word recognition
• computer skills.

Children with Prader-Willi syndrome also tend to be caring and pleasant, with a good sense of humour.

Diagnosis and testing for Prader-Willi syndrome

Health professionals diagnose Prader-Willi syndrome by looking at the physical and other signs listed above. They might also do genetic testing, which involves blood tests.

Early intervention services for children with Prader-Willi syndrome

If your child has Prader-Willi syndrome, early intervention is the best way to support your child’s development. Early intervention includes therapies, education and other supports that will help your child reach their full potential.

Early intervention should also include helping you learn how to spend time with your child in ways that support their development. Children learn the most from the people who care for them and with whom they spend most of their time, so everyday play and communication with you and other carers can help your child a lot.

You and your child will probably work with many health and other professionals as part of your child’s early intervention. These professionals might include behavioural therapists, dietitians, endocrinologists, exercise physiologists , occupational therapists, paediatricians, physiotherapists, special education teachers and speech pathologists.

Working in partnership with your child’s professionals is very important. When you combine your deep knowledge of your child with the professionals’ expertise, you’re more likely to get the best outcomes for your child.

Financial support for children and teenagers with Prader-Willi syndrome

If your child has a confirmed diagnosis of Prader-Willi syndrome, you might be able to get support from the National Disability Insurance Scheme (NDIS). The NDIS can help you get services and support in your community. The NDIS might also fund things like early intervention therapies and assistive technologies.

Looking after yourself and your family

It’s important to look after yourself physically, mentally and emotionally. If you take care of yourself, you’ll be better able to care for your child.

If you need support, you could start by talking with your GP. Your GP is there to give you and your child ongoing care and support.

A genetic counsellor might be able to help you understand how the change in your child’s genes happened. They can also help you learn about the condition and adapt to having a genetic condition in your family.

You can also get support from organisations like Prader-Willi Syndrome Australia, Genetic Alliance Australia and Genetic Support Network of Victoria.

Talking to other parents can be a great way to get support too. You can connect with other parents in a similar situation by joining a face-to-face or an online support group.

If you have other children, they might have a range of feelings about having a sibling with disability. They need to feel that they’re just as important to you as your child with disability – that you care about them and what they’re going through. It’s important to talk with your other children, spend time with them, and find the right sibling support for them.