Massachusetts General Hospital, Herscot Center
Dr. Elizabeth Thiele talks with Angelo and his mom

Tuberous sclerosis complex, or TSC, is a genetic disorder with a wide range of symptoms that can affect people from birth through adulthood. The disorder is caused by a mutation in one of two genes, TSC1 or TSC2. A mutation in either of these genes interferes with the body's ability to control cell growth and division. The disorder can occur sporadically as the result of a spontaneous mutation, or it can be genetically inherited.

TSC affects 1 in 6,000 people worldwide and impacts both sexes and all ethnicities equally. The disorder may cause tumor growth in multiple organ systems, including the brain, skin, eyes, heart, lung, and kidneys. However, TSC's effects vary greatly and are unpredictable from one individual to another, even within the same family. While some people with TSC are cognitively normal and experience minor organ involvement, others are more severely affected with multi-system progressive tumors, intractable epilepsy, and mental retardation.

The neurological manifestations of TSC are often the most debilitating aspects of the disorder. Epilepsy is the most common medical condition associated with TSC. At least 60 percent and possibly more than 90 percent of people affected by TSC experience seizures at some point in their life. People with TSC may also develop learning disabilities and mental health and behavioral problems, such as attention deficit, depression, and autism.

For more information about tuberous sclerosis complex, visit the Herscot Center's Living with TSC Web site.