What is Tuberous Sclerosis

Tuberous Sclerosis (also known as Tuberous Sclerosis Complex or TSC) is a rare genetic disorder that causes benign tumors to grow in the brain and other vital organs, such as the kidneys, heart, eyes, lungs, and skin. While the condition is lifelong, its severity varies greatly among individuals, with symptoms ranging from mild skin findings to complex neurological challenges like epilepsy and developmental delays.

What exactly is Tuberous Sclerosis?

Tuberous Sclerosis is a multisystem genetic condition characterized by the growth of non-cancerous (benign) tumors in multiple organ systems. The name comes from the characteristic "tuber" (potato-like) nodules that form in the brain. Because Tuberous Sclerosis affects the way cells grow and divide, it can impact almost any part of the body, leading to a wide spectrum of clinical presentations. At DiseaseMaps.org, we currently support a community of 351 individuals living with Tuberous Sclerosis, highlighting the diverse ways this condition manifests across different families.

How does Tuberous Sclerosis affect the body?

The effects of Tuberous Sclerosis are systemic, meaning they can involve various organ systems. The most common areas affected include:

• Neurological: Many individuals experience seizures, intellectual disabilities, or behavioral challenges such as autism spectrum disorder or ADHD.


• Dermatological: Skin lesions, such as ash-leaf spots (hypopigmented patches) or facial angiofibromas, are often the first signs observed.


• Renal: Kidney involvement, including angiomyolipomas (benign tumors of blood vessels and fat) and cysts, requires regular monitoring.


• Cardiac: Infants may be born with cardiac rhabdomyomas, which are benign heart tumors that often shrink or disappear on their own over time.


• Pulmonary/Ocular: Less frequently, the lungs (LAM) or the eyes (retinal hamartomas) may be affected.

What causes Tuberous Sclerosis and is it hereditary?

Tuberous Sclerosis is caused by mutations in either the TSC1 or TSC2 genes. These genes are responsible for producing proteins (hamartin and tuberin) that act as "brakes" on cell growth. When these genes are mutated, the "brakes" fail, allowing cells to grow and divide uncontrollably. While it can be inherited in an autosomal dominant pattern, approximately two-thirds of cases arise from a spontaneous (de novo) mutation in an individual with no previous family history of the condition.

How common is Tuberous Sclerosis?

Tuberous Sclerosis is considered a rare disease, with an estimated prevalence of approximately 1 in 6,000 to 1 in 10,000 live births. It affects males and females equally and occurs in all ethnic and geographic populations. Symptoms can appear at any age; while many diagnoses occur in early childhood due to seizures or skin findings, some adults with milder forms may not be diagnosed until much later in life.

Next steps

• Consult a geneticist to confirm the diagnosis through molecular genetic testing.


• Schedule baseline screenings with specialists, including a neurologist, cardiologist, and nephrologist.


• Connect with the 351 members of our Tuberous Sclerosis community on DiseaseMaps.org to share experiences and learn about coping strategies.


• Visit the Tuberous Sclerosis Alliance (TS Alliance) website for the latest information on clinical trials and research.

Medical disclaimer: This content is for informational purposes only and does not constitute medical advice, diagnosis, or treatment; always seek the advice of a qualified physician with any questions regarding a medical condition.

References

• NIH Genetic and Rare Diseases Information Center (GARD): Tuberous Sclerosis Complex.


• Orphanet: Tuberous Sclerosis.


• OMIM (Online Mendelian Inheritance in Man): Tuberous Sclerosis Complex.


• Tuberous Sclerosis Alliance: Clinical Guidelines and Patient Resources.