Tuberous Sclerosis

Tuberous sclerosis causes

Tuberous sclerosis is caused by a pathogenic variant (sometimes called a gene mutation) in either the TSC1 or TSC2 gene. The TSC1 gene instructs the body to produce hamartin, while the TSC2 gene helps produce tuberin.

Those two proteins are tumor suppressors, so when a person has a pathogenic variant in either gene, tumors can grow and spread more easily.

Complications

Just as the symptoms of tuberous sclerosis can vary based on where tumors grow, so do the complications of the disorder. Potential complications of tuberous sclerosis include:

• Arrhythmias: When tumors grow in the heart, they can sometimes cause abnormal heart rhythms.
• Chylothorax: Tumors in the lungs can cause a milky fluid called chyle to build up between the membranes that line the lungs and chest, leading to breathing problems.
• Epilepsy: Many people with TSC develop epilepsy, causing difficult-to-control seizures beginning early in life.
• Hydrocephalus: Tumors in the brain can block the flow of cerebrospinal fluid, causing it to build up in the brain.
• Kidney problems: Noncancerous growths called angiomyolipomas and renal cysts can develop in the kidneys, sometimes causing pain or kidney failure.
• Kidney cancer: Having tuberous sclerosis increases the risk of kidney cancer (renal cell carcinoma), although only 3% of people with TSC develop it.
• Lymphangioleiomyomatosis: Women with TSC may develop this rare lung condition, which causes shortness of breath and other breathing difficulties.
• Outflow tract obstruction: Tumors on the heart can disrupt blood flow from the heart, slowing or obstructing it entirely.
• Pneumothorax: Lung tumors can lead to a partial or total collapsed lung.
• Status epilepticus: Having a seizure lasting for longer than five minutes or multiple seizures in a row without regaining consciousness is considered a medical emergency.

Diagnosing tuberous sclerosis

Your child’s doctor can review your child’s symptoms and determine whether they could be related to TSC or another condition. Doctors can use genetic testing to diagnose your child with tuberous sclerosis, or they may use criteria determined by the International Tuberous Sclerosis Complex Consensus Group.

Using those criteria, your doctor may diagnose your child if they show two major features of TSC, such as multiple retinal tumors, multiple large ash-leaf spots or a heart tumor, or a major feature with two minor features, such as multiple renal cysts or pits in dental enamel.

Tuberous sclerosis treatment

Because there’s currently no cure for TSC, treatment focuses on treating individual symptoms and complications. You and your child will work with a variety of specialists, including pediatric neurologists and neurosurgeons, behavioral health professionals, dermatologists and ophthalmologists, to help ensure your child receives the individualized care they need.

Frequently asked questions