Health A to Z: Noonan syndrome

Noonan syndrome is a condition you're born with.

It affects everyone who has it differently, with some people having more severe problems than others.

People with Noonan syndrome can have problems including:

• chest pain, shortness of breath and tiredness due to a problem with the heart (most people with Noonan syndrome are born with heart disease)
• hearing loss
• vision problems, such as a squint, lazy eye, astigmatism, short-sightedness or long-sightedness
• joint and muscle problems, such as pain, weakness and sideways curvature of the spine (scoliosis)
• bleeding and bruising easily
• swollen hands and feet (lymphoedema)
• a chest that sticks out, sinks in, or is unusually wide
• problems feeding – babies often find sucking difficult and do not gain weight as expected
• taking longer to talk than other children of the same age – some children may also have a mild learning disability
• short height and delayed puberty (boys often have undescended testicles)

People with Noonan syndrome can also have similar facial features, such as widely spaced eyes, drooping eyelids, low-set ears and a wide neck.

Some people with the condition also have conditions that affect the immune system, such as lupus, vitiligo, antiphospholipid syndrome and coeliac disease.

Noonan syndrome is caused by an altered gene.

Sometimes the altered gene is passed on to a child by one of their parents (inherited).

But most children born with Noonan syndrome do not have parents with the condition.

If you have Noonan syndrome, there's a 1 in 2 (50%) chance of passing the affected gene on to any children you have.

See a GP if:

Noonan syndrome is usually diagnosed at birth or in early childhood.

Sometimes you can have Noonan syndrome as an adult without realising because you do not have any of the typical features.

If you have a child with Noonan syndrome, you may be offered a genetic test to see if you also have it. This involves having a blood test to check for one of the altered genes that causes the condition.

If you're pregnant and you, your partner or your child has Noonan syndrome, you may be offered a test, such as amniocentesis or chorionic villus sampling (CVS) to check if your baby also has the condition.

Other tests used to help confirm Noonan syndrome include:

• a test that checks the electrical activity of your heart (electrocardiogram)
• a scan of your heart and nearby blood vessels (echocardiogram)
• blood tests to check for problems with blood clotting (the blood’s ability to thicken and stop bleeding)
• eye tests and hearing tests

Noonan syndrome is a lifelong condition that affects everyone who has it differently.

The condition can cause a range of problems and can be difficult to live with. While some people are mildly affected by it, others are severely affected and have significant health problems.

You or your child should have regular check-ups so that any problems or issues can be closely monitored and treated. If your child has a learning disability, they may also need extra support at school and as an adult.

Many people with Noonan syndrome live for a long time and have a good quality of life. But if you have severe heart problems, it can affect how long you live. Your care team will be able to speak to you about this if you want to know more.

There’s currently no cure for Noonan syndrome, but there are treatments that can help manage some of the problems caused by the condition.

The type of treatment you need will depend on the problems you have and how severe they are.

Treatments include:

• medicines or surgery for heart problems
• medicine to help the blood clot (thicken)
• growth hormone therapy for children with short height
• hearing aids for hearing loss
• glasses for vision problems like short- or long-sightedness
• speech and language therapy to help with any delay in talking

You or your child may need support from a range of healthcare professionals, including a heart specialist (cardiologist), a blood specialist (haematologist) and a hormone specialist (endocrinologist).

Children will also be under the care of a doctor who specialises in the treatment of children (paediatrician).

If you or your child have Noonan syndrome, healthcare professionals will support you throughout your treatment.

You may also find it helpful to get support from other people with Noonan syndrome, or parents of children with Noonan syndrome.

Noonan Syndrome Association

The Noonan Syndrome Association provides a range of support and information for people affected by Noonan syndrome.

• Website: www.noonansyndrome.org.uk
• Noonan Syndrome Association: what we do
• Noonan Syndrome Association: useful factsheets
• Noonan Syndrome Association: member stories