Understand
TSC Is a Lifelong Disease
In different stages of your life, TSC may cause tumors in your brain, kidneys, lungs, heart, skin, and eyes. These tumors are not cancerous, but they can create serious complications if they are not watched and taken care of. Your doctor can help you treat them if they cause problems. TSC can also cause neurologic (brain) issues such as seizures and learning disabilities.

Brain—About 80% of people with TSC have SEN brain tumors, and up to 15% have SEGA brain tumors
Kidneys—About 80% of people with TSC have kidney tumors
Skin—More than 90% of people with TSC experience skin problems
Lungs—Nearly 40% of women with TSC have lung tumors
Heart—About 50% of babies with TSC are born with heart tumors
Eyes—40% to 50% of people with TSC have eye tumors
Teeth—100% of adults with TSC have dental pits in their teeth
SEN, subependymal nodule; SEGA, subependymal giant cell astrocytoma.
Diagnose
How Do Doctors Diagnose TSC?
TSC is a challenge to diagnose and treat because it affects everyone in a different way:
- No 2 people have the same symptoms
- Some people have very mild symptoms, while others have serious ones
- and some people may have just a few tumors in one place, like the kidneys, while others may have many tumors affecting several places, such as the brain and lungs
Doctors will make a definite diagnosis of TSC if you have:
- 2 major areas affected
- or 1 major and 2 minor areas affected
Doctors will make a possible diagnosis (meaning you might have TSC) if you have:
- Either 1 major area affected or 1 major and 1 minor area affected
- or at least 2 minor areas affected
Common Areas Affected by TSC
TSC complications are divided into major and minor signs based on how common they are. The major signs occur in the majority of people with TSC, and the minor ones occur in smaller percentages of people. This separation of major and minor signs helps doctors determine who has TSC.
Brain
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Major
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Kidneys
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Major
Minor
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Skin
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Major
Minor
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Lungs
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Major
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Heart
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Major
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Eyes
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Major
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Teeth
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Minor
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Other areas
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Minor
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What Is the Cause?
TSC can occur randomly; 2 of every 3 people with TSC have the genetic disorder that developed on its own, without a family connection.

One of every 3 people with TSC has the genetic disorder passed down from a parent.

How Do People Get TSC?
There are about 20,000 genes in everyone’s body. Each person has genes called TSC1 and TSC2. These genes make proteins to control mTOR and control cell growth.
People with TSC have a defect in TSC1 and TSC2, so their bodies do NOT make proteins to control mTOR. Cells grow out of control, and tumors or seizures can happen.
mTOR, mammalian target of rapamycin.
The Story of TSC
Watch a short animated film about how TSC occurs.
The Story of TSC
Watch a short animated film about how TSC occurs.