Tuberous sclerosis causes non-cancerous (benign) tumours to develop in many areas of the body. The condition can lead to a range of different problems depending on where the tumours grow.

The areas most commonly affected are the: 

• brain
• skin
• kidneys
• heart
• eyes
• lungs

Problems caused by these tumours can develop at any age, but most often start early in childhood. The severity of these problems can vary significantly, and some tumours cause no noticeable problems.

The main problems these tumours can cause are described below.

Problems affecting the brain

Tumours that develop in the brain can cause a range of problems.

Epilepsy and spasms

Most people with tuberous sclerosis will have epilepsy and experience repeated seizures (fits).

Some young children experience a more serious condition, known as infantile spasms, where they have lots of seizures over a short space of time and brain activity is abnormal all the time. These usually develop during the first year of life.

Infantile spasms tend to disappear as a child gets older but, by then, they may have led to some degree of permanent brain damage, which can cause problems such as moderate to severe intellectual disability, epilepsy that does not respond to medication, and autism.

It's important for infantile spasms to be identified as early as possible, as early treatment markedly reduces the risk of brain damage.

Learning disabilities

Nearly half of all children with tuberous sclerosis will have a learning disability, which can range from mild to severe.

Possible problems include: 

• poor memory
• poor attention span
• difficulty making plans or organising activities
• learning much more slowly than other people
• in severe cases, being unable to communicate or look after themselves

Read more about learning disabilities.

Behavioural and developmental disorders 

Behavioural and developmental disorders are more common in children with tuberous sclerosis, particularly those with learning disabilities.

These problems can include: 

• autism spectrum disorder – a condition that affects social interaction, communication, interests and behaviour
• hyperactivity and impulsive behaviour
• aggression and self-harm
• anxiety
• extreme shyness
• depression
• sleep disorders – such as finding it difficult to get to sleep or frequently waking up during the night

Hydrocephalus

A small number of people with tuberous sclerosis develop large brain tumours that grow big enough to obstruct the flow of cerebrospinal fluid through the brain.

If the flow of cerebrospinal fluid is blocked, it can cause pressure to build in the brain. This is called hydrocephalus. Symptoms can include:

• headaches
• neck pain
• feeling and being sick
• increasing drowsiness
• changes in your mental state, such as confusion
• blurred vision, double vision or loss of vision
• difficulty walking
• a sudden change in bladder or bowel control, such as urinary incontinence
• worsening epilepsy or challenging behaviour

Brain tumours can be detected through regular brain scans and treated before they cause hydrocephalus.

If hydrocephalus develops, emergency surgery is required to drain away excess fluid from the brain. If left untreated, it can cause brain damage or, in the most serious cases, death.

Skin problems

Most people with tuberous sclerosis will have abnormal growths or patches on their skin. They usually first develop during early childhood and can include:

• patches of light-coloured skin
• red, acne-like spots and blemishes on the face
• areas of thickened skin
• growths of skin under or around the nails

Kidney problems

Most people with tuberous sclerosis will have multiple growths in their kidneys, including tumours and cysts (small fluid-filled sacs).

These do not always cause problems but can lead to:

• internal bleeding – this can cause blood in pee and sudden, severe pain in the tummy
• high blood pressure (hypertension)
• kidney failure, which can cause symptoms such as weight loss, swollen ankles, feet or hands, shortness of breath, an increased need to pee and itchy skin
• in rare cases, kidney cancer

Heart tumours

Many children born with tuberous sclerosis will develop one or more tumours inside their heart.

These tumours are usually very small and do not cause any symptoms. Most heart tumours will shrink as a child gets older.

However, in a small number of cases, the tumours can cause problems such as an irregular heart beat (arrhythmia) or heart failure.

Eye tumours

Most people with tuberous sclerosis will develop one or more tumours inside their eyes.

These tumours grow on the surface of the retina, which is the thin layer of nerve cells that line the inside of the back of the eye.

However, these tumours rarely grow large enough to affect a person's vision.

Lung tumours

At least 1 in every 3 women with tuberous sclerosis will develop tumours and cysts inside their lungs, usually between the ages of 20 and 40. It's unclear why women are commonly affected and men rarely are.

In many cases, these cysts and tumours do not cause a problem.

However, some women experience breathing difficulties similar to chronic obstructive pulmonary disease (COPD) and occasionally the tumours can rupture, causing a serious problem where air leaks out of the lungs and into the surrounding area.

To diagnose tuberous sclerosis, you'll be asked about your family's medical history. You'll also have a number of tests to look for signs of the condition.

Healthcare professionals use a checklist of the characteristic features of tuberous sclerosis – such as abnormal areas of skin, or tumours in your eyes, brain, heart, lungs or kidneys – to confirm a diagnosis. Several tests will be needed to check for these features.

Finding out about your family's medical history is also important because tuberous sclerosis can sometimes run in families.

Tests for tuberous sclerosis

Tests you may have to check for tuberous sclerosis include:

• an eye examination – to check for eye tumours
• a skin examination – to look for abnormal growths or patches of pale or thickened skin
• an MRI scan – to detect tumours in the brain or kidneys
• a CT scan or ultrasound scan – to detect tumours in the kidneys, heart or lungs
• an electroencephalogram (EEG) – to detect abnormal electrical activity within the brain associated with epilepsy
• an electrocardiogram (ECG) – to detect abnormal electrical activity in the heart that could be caused by heart tumours

A genetic blood test to look for the faulty genes that cause tuberous sclerosis can also help make a diagnosis, although it isn't always reliable.

Tuberous sclerosis is a lifelong condition that requires long-term care and support from a range of different healthcare professionals.

If your child is affected, an individual care plan will be drawn up to address any needs or problems they have. As your child gets older, the plan will be reassessed to accommodate changes to their needs or situation.

Their care plan is likely to include details about any treatment or support they need, as well as the routine tests that will be necessary to monitor their condition.

Read on to learn about how tuberous sclerosis is monitored, and some of the treatments available.

Monitoring the condition

Regular testing is important for people with tuberous sclerosis. This is so the function of the organs often affected by the condition – such as the brain, kidneys and lungs – can be regularly monitored and assessed.

Tests and checks that may be recommended include:

• MRI scans – to check for changes in tumours in the brain or kidneys
• ultrasound scans – to check for heart and kidney tumours
• blood tests – to check how well the kidneys are working and other things, such as vitamin D levels
• electrocardiograms (ECGs) – to detect abnormal electrical activity in the heart
• CT scans – to check the function of the lungs, such as measuring how much air a person can breathe out
• skin and eye examinations – to look for any changes
• blood pressure measurements
• questions about your child's behaviour and development

How often these tests are needed will depend on your or your child's age and the symptoms they have. Some are carried out annually, while others are done once every few years.

Epilepsy

Epilepsy is a very common feature of tuberous sclerosis and can sometimes be difficult to control.

Medications to control the seizures (anti-epileptic drugs) will usually be tried first, although they're not always effective for people with tuberous sclerosis.

If the first medicine isn't effective, the dose can be increased. You can also try a different medicine, or you may be prescribed two medicines to take at once.

If medication doesn't control the seizures, one of the following procedures may be recommended:

• surgery to remove any tumours in your brain that may be causing the seizures
• vagus nerve stimulation (VNS) – where a small electrical device is implanted under the skin to send pulses of electricity to the brain
• a special diet – the ketogenic diet or a modified version of it

Read about treatments for epilepsy for more information.

Behavioural and learning problems 

If your child is experiencing behavioural problems or has a learning disability, they may be referred to a psychologist for an assessment.

A special educational needs plan may be drawn up to outline any extra educational support your child may require.

For some children, it may be possible for extra support to be given at a mainstream school, while others may benefit from attending a special school.

Read more about children with a learning disability and special educational needs.

Brain tumours

Any brain tumours will be detected and monitored closely so treatment can be carried out if necessary.

A brain tumour may need to be surgically removed if there's a risk it could get too big and cause a build-up of fluid on the brain (hydrocephalus).

Research has also found that a medication called everolimus shrinks most brain tumours, preventing them from causing hydrocephalus and potentially improving epilepsy as well.

Everolimus is a type of mTOR inhibitor, which interrupts or blocks the chemical reactions needed for tumours to grow. They are a useful treatment for some of the problems caused by tuberous sclerosis.

Long-term studies carried out over several years have shown them to be very effective and longer-term studies are under way.

Skin problems

Abnormal growths or patches of skin don't usually present a serious health problem, but their appearance can affect a person's confidence and self-esteem.

Laser therapy can be used to improve the appearance of the skin if necessary. If the growths or patches return, repeated laser therapy may be required. Using sun cream is also important to protect the skin.

Research has shown the effectiveness of mTOR inhibitor cream in treating skin abnormalities caused by tuberous sclerosis. The rash also usually shows significant improvement in those taking mTOR inhibitors as tablets for their kidneys or brain tumours.

Kidney tumours

Treatment for kidney tumours and growths will depend on the problems they cause.

For example, if kidney tumours cause high blood pressure (hypertension), medicine can be used to help lower it. Read more about treating high blood pressure.

Everolimus may be used to stop tumours becoming too large, as large tumours can cause dangerous bleeding. However, as this is a relatively new treatment, the long-term effects are not yet fully known.

If a tumour bleeds, a procedure called embolisation may be recommended. A special substance is injected into the tumour to block its blood supply, which starves it of oxygen and nutrients, causing it to shrink.

Very rarely, if you have a severe or total loss of kidney function, you may require dialysis or a kidney transplant.

Heart tumours

In most cases, heart tumours will not need treatment. Heart tumours in babies usually shrink as the child gets older, until they are barely detectable as adults.

However, in some rare cases, surgery may be required to remove the tumours if they begin to seriously affect the functioning of the heart.

Sometimes, the heart tumours affect the electrical conduction on the heart and cause abnormal heart rhythms. These problems occasionally need treatment with medication.

Lung tumours

Women with lung tumours may require medication to shrink the tumours.

Research has shown that an mTOR inhibitor called sirolimus is effective, although it can cause side effects such as feeling sick, and constipation or diarrhoea. It's available to treat lung tumours caused by tuberous sclerosis through the National LAM Centre at the University Hospital of Nottingham.

If lung tumours lead to a collapsed lung, emergency surgery is required to repair the lung and drain any air that has escaped into the chest.

In very severe cases, a lung transplant may be required.

Eye tumours

Eye tumours rarely need any treatment, because they usually do not grow big enough to impair vision. In rare cases where vision is affected, a technique called photocoagulation can be used.

Photocoagulation is a type of surgery that uses lasers to burn away the blood vessels supplying the eye tumours with blood. Blocking the blood supply should shrink the tumours.