Tuberous Sclerosis and Tuberous Sclerosis Clinic

What is Tuberous Sclerosis Complex?
How Many People Have TSC?
How Does a Person Develop TSC?
What Causes TSC?
How is TSC Diagnosed?
Are the Tumors That Can Result from TSC Cancerous?
What is the Normal Life Expectancy of a Person with TSC?
Since There is No Cure, What Can Be Done?
About the TSC Clinic at Children's Hospital of Pittsburgh
Where Can I Find More Inforamtion?

What is Tuberous Sclerosis Complex?

Tuberous sclerosis complex (TSC) is a genetic condition commonly characterized by seizures and tumor growth in vital organs such as the heart, kidneys, lungs and skin. The disorder affects some people severely, while others are so mildly affected that it often goes misdiagnosed or undiagnosed.

Some people with TSC experience developmental delay, mental retardation or autism. However, many people with TSC also live independent, healthy lives and enjoy challenging professions.

How Many People Have TSC?

TSC affects nearly 50,000 people in the United States and more than one million people worldwide. At least two children born each day will have TSC. Current estimates place TSC-affected births at one in 6,000 live births.

Many cases of the disorder go undiagnosed due to lack of familiarity with the disease among physicians and the general public and the mild symptoms some people experience. TSC is as common as Lou Gehrig’s Disease (ALS), but still virtually unknown by the general population.

Top

How Does a Person Develop TSC?

TSC is either inherited or transmitted as a spontaneous change in genetic material, called a mutation. Children have a 50 percent chance of inheriting TSC if one of their parents has the condition, but only one-third of TSC cases are known to be inherited. The other two-thirds are believed to be a result of spontaneous mutation. The cause of the mutations is still a mystery.

People with mild cases of TSC can have a child who is more severely affected. In fact, some people are so mildly affected that they may go undiagnosed until their more severely affected child is diagnosed with TSC.

What Causes TSC?

Two genes cause TSC, and only one of the genes needs to be affected for TSC to be present. The TSC1 gene is located on chromosome 9, the same chromosome carrying the gene that determines blood type. The TSC2 gene is located on chromosome 16. TSC occurs when an individual has a mutation in either the TSC1 or TSC2 gene. The mutation can be inherited from one parent or can be a new mutation that develops within the person.

Recent studies have shown that in cases in which two or more people in a family have TSC, about 50 percent have a mutation in TSC1 and the other 50 percent have a mutation in TSC2. This research also has shown that, in cases in which no prior family history of TSC exists, more individuals have a mutation in the TSC2 gene than in the TSC1 gene.

Top

How is TSC Diagnosed?

TSC is diagnosed both by clinical findings and also genetic testing. Some of the tests used to help make the diagnosis are a brain magnetic resonance imaging (MRI) or computerized tomography (CT) scan, renal (kidney) ultrasound, echocardiogram, electrocardiogram (EKG), eye exam and a Wood’s lamp (ultraviolet light) evaluation of the skin. Genetic testing is available for any patient who has TSC and would like to know more about their genetic mutation or for those patients where the diagnosis for TSC is questionable. Family members of patients with TSC are also able to be tested.

Are Tumors That Can Result from TSC Cancerous?

The tumors resulting from TSC are generally benign, but still may cause problems. Tumors that grow in the brain can block the flow of cerebrospinal fluid in the spaces (ventricles) in the brain. This can lead to behavior changes, vomiting, headaches, changes in gait, and, if untreated, even death.

In the heart, the tumors are usually at their largest at birth, and then decrease in size as the person gets older. These heart tumors (cardiac rhabdomyomas) can cause problems at birth if they are blocking the flow of blood or causing severe heart rhythm problems. Tumors in the eyes are not as common, but can present problems is they grow and block too much of the retina (back of the eye). Tumors in the kidney (renal angiomyolipomas) can become so large that they eventually take over all the normal kidney functions. In the past, patients were left untreated until they developed kidney failure. Today, doctors are more aggressive and remove individual tumors before they get too large and compromise healthy kidney tissue. Individuals with TSC rarely (less than 2 percent) develop cancerous (malignant) kidney tumors.

Top

What is the Normal Life Expectancy of a Person with TSC?

Most people with TSC will have a normal life span. There can be complications in organs such as the kidneys and brain that can lead to severe difficulties and even death if left untreated. To reduce these dangers, individuals with TSC should be monitored by their physicians for potential complications throughout their lives.

Since There is No Cure, What Can Be Done?

Early intervention is helping to diminish the impact of developmental delay on day-to-day functioning and an person’s ability to reach his or her maximum potential. Advances in research are resulting in new and improved therapies. Surgery to remove tumors is helping to preserve the function of affected organs. Improved technology is helping to pinpoint the regions of the brain responsible for seizures in particular patients, and is creating new therapies to help control or even stop these seizures in those patients.

About the TSC Clinic at Children's Hospital of Pittsburgh of UPMC

The Tuberous Sclerosis Clinic at Children's Hospital of Pittsburgh is directed by Deborah Holder, MD. This clinic meets the third Wednesday of each month. To make an appointment, please contact Neurology Scheduling at 412-692-5520.

Where Can I Find More Information?

Top
Updated 10/8/07