What is Smith-Magenis syndrome?

Smith-Magenis syndrome (SMS) is caused by some missing genes on chromosome 17, or by changes or abnormalities in a gene on chromosome 17.

This genetic change happens around the time of conception. Smith-Magenis syndrome isn’t usually inherited.

Smith-Magenis syndrome is rare. It occurs in about 1 in 25 000 people, and affects boys and girls equally.

Children with Smith-Magenis syndrome are often also diagnosed with autism spectrum disorder, attention deficit hyperactivity disorder, obsessive compulsive disorder and mood disorders.

Signs and symptoms of Smith-Magenis syndrome

Physical characteristics
Children with Smith-Magenis syndrome can have:

  • facial features that include a broad, square face with deep-set eyes, full cheeks, a prominent lower jaw, a flattened bridge of the nose, a downturned mouth, and eyes looking in different directions (strabismus)
  • low muscle tone
  • short stature
  • curved spine (scoliosis)
  • hoarse voice
  • myopia (short-sightedness)
  • flat feet.

Cognitive signs
Children with Smith-Magenis syndrome can have:

  • developmental delay
  • mild to moderate intellectual disability
  • speech delay.

Behavioural signs
Children with Smith-Magenis syndrome often have:

  • sleep problems – for example, they might sleep during the day and be awake at night
  • temper tantrums
  • aggression problems
  • anxiety
  • attention difficulties
  • a tendency to injure themselves deliberately
  • a tendency to hug themselves repeatedly
  • reduced sensitivity to pain and temperature
  • eating difficulties, with a preference for soft foods.

Medical concerns linked to Smith-Magenis syndrome
Children with Smith-Magenis syndrome can have other medical concerns like:

  • ear abnormalities (sometimes leading to hearing loss)
  • heart and kidney defects
  • retinal detachment.
Most children with Smith-Magenis syndrome have good long-term memory, happy and endearing personalities, and a good sense of humour.

Diagnosis and testing for Smith-Magenis syndrome

Health professionals diagnose Smith-Magenis syndrome by looking at the physical and other signs and symptoms listed above. They usually confirm the syndrome with genetic testing.

Early intervention services for children with Smith-Magenis syndrome

Although there’s no cure for Smith-Magenis syndrome, early intervention can make a difference. Through early intervention services, you can work with health professionals to treat your child’s symptoms, support your child, improve outcomes for your child and help your child reach her full potential.

The team of professionals involved in supporting you and your child might include paediatricians, psychologistsspeech pathologists, physiotherapists, occupational therapists and special education teachers.

Together, you and your team can choose treatment and therapy options to best help your child.

Services and support for children with Smith-Magenis syndrome

Getting information
Learning as much as possible from your specialists will help. It’s OK to ask lots of questions.

Many services and supports can help your child with Smith-Magenis syndrome achieve his potential. But finding your way through the disability services system can be tricky. Our Disability Services Overview can help.

Financial support
If you live in a National Disability Insurance Scheme (NDIS) trial area and your child has a confirmed diagnosis of Smith-Magenis syndrome, your child can get support under the NDIS. The NDIS helps you get services and support in your community, and gives you funding for things like early intervention therapies or one-off items like wheelchairs.

If you don’t live in one of the NDIS trial areas, your child can get funding under the Better Start for Children with Disability initiative. If your child is eligible for the NDIS, she’ll be moved over when it becomes available in your area. Read our NDIS and Better Start FAQs.

Looking after yourself and your family

If your child has Smith-Magenis syndrome, it’s easy to get caught up in looking after him. But it’s important to look after your own wellbeing too. If you’re physically and mentally well, you’ll be better able to care for your child.

If you need support, a good place to start is with your GP and genetic counsellor. You can also get support from organisations like  Genetic Alliance Australia.

Looking after siblings
Siblings of children with disability have good times and not so good times, just like everyone else. It’s important to find the right support for them too.

Talking to other parents can be a great way to get support. You can connect with other parents in a similar situation in local support groups or in forums online.