Tuberous sclerosis

Introduction

Tuberous sclerosis, also known as tuberous sclerosis complex, is a rare genetic condition that causes benign (non-cancerous) tumours to develop in different parts of the body. Tumours can develop on the skin and in the: 

  • brain
  • heart
  • eyes
  • kidneys
  • lungs

There is currently no cure for tuberous sclerosis, but there is a range of treatments for many of the associated symptoms (see Tuberous sclerosis - treatment). New research is also showing that medicines called mTOR inhibitors may have important benefits in the future.

Associated conditions and complications

The benign tumours that develop from tuberous sclerosis can cause a range of other associated health conditions and complications. These include:

  • epilepsy – a condition that causes seizures (fits)
  • intellectual impairment, such as below-average intelligence 
  • learning disabilities 
  • behavioural problems, such as hyperactivity or autism (a developmental disorder that causes problems with language and social interaction)
  • skin abnormalities, such as patches of light coloured or thickened skin, or red acne-like spots
  • heart problems
  • kidney disease
  • lung problems
  • hydrocephalus – a build-up of fluid on the brain, which can put pressure on the brain and damage it 

The range and severity of the associated health conditions caused by tuberous sclerosis can vary significantly from person to person, even among members of the same family.

For example, some people with tuberous sclerosis do not have many symptoms and the condition has no real impact on their quality of life. For others, tuberous sclerosis may severely affect their intellectual development or cause life-threatening complications such as lung failure, and require life-long care.

See Tuberous sclerosis - symptoms for more information.

Who is affected by tuberous sclerosis?

Tuberous sclerosis is a rare condition that affects 1 in every 6,000 live births worldwide. The condition is caused by mutations (changes) in one of two genes. These are:

  • the TSC1 gene, or 
  • the TSC2 gene

As both of these genes are involved in regulating cell growth, it is thought that the mutations are responsible for causing multiple benign tumours to develop. In around a quarter of cases, a child inherits one of the mutated genes from one of their parents. In the other 75% of cases, the mutation that causes tuberous sclerosis occurs for no apparent reason.

Both sexes and all ethnic groups are equally affected by the tuberous sclerosis. See Tuberous sclerosis - causes for more information.

Outlook

The outlook for people with tuberous sclerosis depends on several main factors:

  • whether the mutation occurred in the TSC1 or TSC2 gene – people with a mutated TSC2 gene may have more serious and wide-ranging symptoms, such as epilepsy or multiple kidney tumours
  • being born with low intelligence – children born with low intelligence usually have epilepsy that does not respond to medication, and they often have associated behavioural problems, such as autism or aggressive outbursts
  • how severely a child is affected at first – the severity of the condition is usually clear by the time a child is five years old
  • a new treatment – new medicines, called mTOR inhibitors, may improve the outlook

Most people with tuberous sclerosis will live a normal life span, but a number of complications may develop and can be fatal (see Tuberous sclerosis - complications).

People with epilepsy that is difficult to treat are at risk of a condition called sudden unexpected death in epilepsy (SUDEP). This affects about 1 in every 250 people with difficult epilepsy every year. Other serious problems that can occur later include hydrocephalus, kidney or lung problems.

Last updated: 31 January 2012

Continue to next section: Causes of tuberous sclerosis

Back to top