Tuberous sclerosis complex is a genetic disorder characterized by the growth of numerous noncancerous (benign) tumors in many parts of the body. These tumors can occur in the brain, kidneys, heart, skin, and other organs, in some cases leading to significant health problems. Tuberous sclerosis complex also causes developmental problems, and the signs and symptoms of the condition vary from person to person.

Variants (also known as mutations) in the TSC1 or TSC2 gene can cause tuberous sclerosis complex. The TSC1 and TSC2 genes provide instructions for making the proteins hamartin and tuberin, respectively. Within cells, these two proteins work together to help regulate cell growth and division (proliferation) and cell size. The proteins act as tumor suppressors, which normally prevent cells from growing and dividing too fast or in an uncontrolled way.

Tuberous sclerosis complex affects 1 in 6,000 to 10,000 people.

Tuberous sclerosis complex has an autosomal dominant pattern of inheritance, which means one copy of the altered gene in each cell is sufficient to increase the risk of developing tumors and other problems with development. In about one-third of cases, an affected person inherits an altered TSC1 or TSC2 gene from a parent who has the disorder. The remaining two-thirds of people with tuberous sclerosis complex are born with new variants in the TSC1 or TSC2 gene. These cases, which are described as sporadic, occur in people with no history of tuberous sclerosis complex in their family. TSC1 gene variants appear to be more common in familial cases of tuberous sclerosis complex, while variants in the TSC2 gene occur more frequently in sporadic cases.

Published Date: January 04, 2022
Published By: National Institutes of Health