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Tuberous Sclerosis Complex (TSC)

What is tuberous sclerosis complex?

Tuberous sclerosis complex (TSC) is a genetic condition that affects many organs and can cause tumors in the skin, kidney, brain, heart, eyes, lungs and other organs. The severity of TSC can range from mild, such as skin abnormalities, to severe, such as seizures, intellectual disability or renal failure. The most common symptoms of TSC are seizures and developmental delay as well as benign tumors and skin lesions. TSC can affect virtually every organ system of the body including the brain, kidneys, heart, lungs, eyes, skin, and other organs. In many instances, symptoms of TSC will be apparent in the first six months of life.

Who gets tuberous sclerosis complex?

TSC affects approximately 50,000 people in the United States and one million worldwide, with an estimated incidence of 1 in 6,000 live births.

What causes tuberous sclerosis complex?

TSC is caused by a mutation (gene change) in one of two genes: TSC1 and TSC2. Genetic testing for TSC, at this time, is able to detect mutations in the TSC1 or TSC2 genes in approximately 90% of individuals. For the other 10% of individuals without an identifiable mutation, researchers are studying ways to accurately find mutations in these two known genes and look for additional genes that may be involved.

How is tuberous sclerosis complex diagnosed?

Clinical diagnosis of TSC is based on a careful physical exam in combination with imaging of the brain, heart and kidneys. The physician will carefully examine the skin for the wide variety of skin lesions, often using an ultraviolet light called a Wood’s lamp which may be useful for finding skin features that can be hard to see on infants or individuals with pale skin.

There is no single clinical feature specific to the condition. In addition, many features of TSC, such as seizures and developmental delay, are seen in individuals without TSC. Therefore, a constellation of features is necessary for the diagnosis, and an increasing number of features make the clinical suspicion of TSC more likely.

Recently, genetic testing for TSC has become more readily available, and a positive genetic test can be considered diagnostic.

What is the treatment for tuberous sclerosis complex?

While, unfortunately, there is no cure for TSC yet, effective treatments are available for a variety of the symptoms. Drugs to prevent seizures are accessible to individuals and surgery can often correct skin abnormalities. Everolimus and sirolimus are newer medications that have been approved to treat some tumors and conditions caused by TSC. Surgery to remove tumors can help to preserve the function of affected organs. For other symptoms of TSC, such as developmental delay, services such as early intervention, special education and other therapies are often effective in moderating symptoms.

Frequently Asked Questions

Why did I get tuberous sclerosis complex?

In general, one third of individuals with TSC inherit the genetic condition from a parent. Two thirds of all cases are de novo, or occur for the first time in a family.

TSC is inherited as an autosomal dominant genetic condition. This means that a mutation in only one copy of the gene causes the condition. Individuals with TSC have a 50% chance of passing their condition to each of their children.

The prognosis of individuals with TSC varies from individual to individual. The severity of the complications determines the long-term outlook, and symptoms can range from mild to severe. Most individuals, who are mildly affected with TSC and are under an experienced physician’s care, can expect to live active and productive lives with normal life expectancy.

In some people, certain symptoms associated with TSC become less severe over time. Individuals with TSC are monitored by their doctors yearly for any changes.

TSC is a genetic disorder and is not caused by an allergy.

TSC is a genetic disorder and is not caused by an injury.

TSC can affect many different organs in the body. Individuals with TSC should be carefully monitored by their physicians for any changes in their symptoms.