Embarrassing Illnesses

The non-cancerous (benign) tumours caused by tuberous sclerosis can occur almost anywhere in the body. However, the areas that they most commonly affect are listed below.

• Skin (occurring in an estimated 90% of all cases).
• Kidneys (occurring in an estimated 80% of all cases).
• Brain (occurring in an estimated 80% of all cases).
• Heart (occurring in an estimated 50-70% of all cases).
• Eyes (occurring in an estimated 50% of all cases).
• Lungs (occurring in an estimated 25-40% of all cases).

Neurological conditions and complications

Tumours that develop in the brain can affect the normal working of the brain and cause a range of neurological conditions and complications.

Epilepsy

Epilepsy is the most common neurological symptom of tuberous sclerosis, affecting an estimated 70-80% of people with the condition. Epilepsy is a condition that causes repeated seizures (fits) and a temporary loss of consciousness. See the Useful links section for more information about epilepsy.

Infantile spasms

Around 10-20% of children will develop a more severe form of epilepsy known as infantile spasms. Infantile spasms usually develop during the first three months following birth.

The condition causes the baby to experience multiple seizures in a short space of time, with the seizures often lasting only a few seconds. A baby usually experiences a ‘run’, or ‘cluster’, of around 20 seizures, although some babies can experience up to 100 seizures over a short period of time.

The symptoms of infantile spasms usually go away by the time a child is three years of age, but the condition often causes permanent brain damage. An estimated 64% of children who experience infantile spasms will go on to develop some degree of brain damage and impaired intelligence.

Low intelligence

Around 30% of children with tuberous sclerosis will be born with significantly below-average intelligence. Intelligence is usually measured using a rating system known as intelligence quotient (IQ) and an average intelligence would be an IQ of 100.

However, children affected by tuberous sclerosis tend to have an IQ of between 30-40, which means that they will have a significant mental disability and profound learning difficulties.

Children who are born with low intelligence also often have associated behavioural problems including:

• hyperactivity,
• impulsive behaviour,
• aggressive outbursts,
• autism,
• anxiety,
• extreme shyness, and
• depression.

Around 50% of children with tuberous sclerosis will be born with average intelligence, but they may also have one or more learning difficulties including:

• poor memory,
• low attention span, and
• difficulty making plans or organising their activities.

Subependymal giant cell astrocytomas (SEGAs)

An estimated 5% of people with tuberous sclerosis will develop multiple types of large benign brain tumours, which are known as subependymal giant cell astrocytomas (SEGAs). Although SEGAs can occur at any age, they are most common after adolescence.

If SEGAs grow too big, there is a risk that they will obstruct the flow of cerebrospinal fluid (CSF) through the brain. Cerebrospinal fluid is a clear fluid that surrounds and protects the brain and spine.

If the flow of CSF is blocked, it can lead to an increase of pressure on the brain, which is known as hydrocephalus. Symptoms of hydrocephalus include:

• headache,
• nausea and vomiting,
• lack of appetite,
• increased irritability, lethargy or drowsiness,
• changes in personality,
• disorientation,
• visual problems, such as double or blurred vision,
  fits and seizures, and
• a sudden change in continence patterns, e.g. urinary incontinence in a person with no previous history of the condition.

Emergency surgery is required to drain away any excess fluid from the brain. If left untreated, hydrocephalus can cause brain damage or, in the most serious of cases, death. See the Useful links section for more information about hydrocephalus.

Skin lesions

Around 90% of people with tuberous sclerosis will develop skin lesions. They usually occur during early childhood and can take the form of patches of light coloured skin, areas of thickened skin and growths of skin under or around the nail. Acne-like spots and blemishes are also common.

Heart tumours

An estimated 50-70% of infants born with tuberous sclerosis will develop one or more benign tumours inside their heart. These tumours are usually very small and do not cause any symptoms. Unlike the other types of tumour that are caused by tuberous sclerosis, heart tumours will usually shrink and disappear as a child gets older.

However, in as estimated 2-4% of children, the tumours can block the flow of blood inside the heart, causing it to beat irregularly (arrhythmia).

Heart problems can also cause associated symptoms including:

• palpitations,
• dizziness,
• fainting,
• breathlessness, and
• chest pains.

Kidney tumours

An estimated 80% of children with tuberous sclerosis will develop multiple benign tumours within their kidneys, usually by the age of five. These kidney tumours are called angiomyolipomas (AMLs) and are made up of blood vessels, muscle and fat.

If the AMLs become too large, they can interfere with the workings of the kidneys and cause symptoms similar to kidney disease including:

• tiredness,
• swollen ankles, feet or hands (due to water retention),
• shortness of breath,
• blood and/or protein in the urine,
• an increase need to urinate (particularly at night),
• itchy skin, and
• nausea.

There is also a chance that an AML could rupture (split) and lead to internal bleeding. If this occurs, it will cause sudden pain and may require surgery to repair.

About 20% of children with tuberous sclerosis will also develop multiple cysts (fluid-filled sacs) in their kidneys. Kidney cysts usually cause no symptoms. However, approximately 5% of people with tuberous sclerosis will develop multiple cysts and may experience symptoms of high blood pressure (hypertension) and kidney disease.

Less than 1% of people with tuberous sclerosis will develop a type of kidney cancer known as renal cell carcinoma. See the Useful links section for more information about kidney cancer.

Lung tumours

An estimated 25-40% of people with tuberous sclerosis will develop non-cancerous tumours and cysts inside their lungs. In most cases, these cysts and tumours do not cause a problem.

Women with tuberous sclerosis have a small risk of developing a serious lung condition called lymphangioleiomyomatosis (LAM). Around 3% of women with tuberous sclerosis will develop LAM, usually during adulthood. It is not clear why women are particularly vulnerable to LAM and men are not.

LAM can cause shortness of breath and, in the most serious cases, one, or more of the tumours can rupture resulting in a collapsed lung. A collapsed lung can occur as a result of injury, or illness, and is where air leaks out from inside the lung. This can be life threatening.

Eye tumours

An estimated 50% of people with tuberous sclerosis will develop one or more benign tumours inside their eyes. The tumour(s) grow on the surface of the retinas but they rarely grow large enough to affect a person’s vision.