By: Andrew Yee
What Is Tuberous Sclerosis?
Tuberous Sclerosis is a lifelong genetic disorder with about one million cases worldwide that can take many years to develop and show symptoms. Also known as Tuberous sclerosis complex (TSC), it is an uncommon genetic disorder that causes noncancerous tumors to grow throughout your body. Symptoms vary widely depending on the types of tumors, their size, and their location (Tuberous Sclerosis: What It Is).
What Causes TSC?
TSC is a genetic disorder caused by mutations in genes. These mutations occur in either the TSC1 or TSC2 gene (Tuberous Sclerosis, Mayo Clinic, 2022). These genes are known to regulate cell growth and development. When the TSC gene is mutated, the gene does not function properly, resulting in cells growing too fast and/or dividing too much (Ranke et al., 2017). This results in benign tumors, also known as a group of dead cells, to develop. The mutation is considered random, meaning it does not affect a particular sex or race (Tuberous Sclerosis Complex). About ⅓ of the mutations occur in offspring from parents who have the disorder and ⅔ by chance (Tuberous Sclerosis. Mayo Clinic, 2022).
These mutations often occur during the fetal process and result in the condition being present at birth. Some cases may be detected as the child develops, and some can go unnoticed for years.
Effects/Symptoms
Tuberous sclerosis is a condition that allows cells to grow and reproduce faster than they should. This leads to growth and tumors in many places in and around your body. The most common place for TSC to occur is in the brain, but it can also affect the heart, kidneys, and skin.
Symptoms
The symptoms of TSC can vary from mild to severe, depending on the organs or body parts affected. The size and location of the tumors will also result in different symptoms. While symptoms are different for everyone, they tend to fall into three categories (Tuberous Sclerosis: What It Is):
● Brain-related symptoms.
● Skin-related symptoms.
● Changes to internal body parts.
Brain-related Symptoms:
Brain-related symptoms occur when tumors are developed in your brain. These tumors can disrupt your brain functions and processing despite being benign. These include (Tuberous Sclerosis):
● Subependymal Giant Cell Astrocytoma (SEGA): A tumor that grows on the ventricular system. These tumors are made of cells called astrocytes and can block the flow of fluids in the brain. This can cause fluids to build up around the brain and cause hydrocephalus. Symptoms include headaches, nausea, and large head size (NCI).
● Cortical Tubers (hamartomas): Cortical Tubers are groups of noncancerous cells located in the brain. They appear in different locations than their corresponding functions because TSC causes the rapid growth of cells, leaving little space for cortical tuber cells. Cortical tubers can change nerve cells and cause irregular impulses, often resulting in Epilepsy.
● Seizures: A seizure in small children, often called an infantile spasm, can occur from TSC. This is caused by abnormal electrical impulses in the brain, usually from cortical tubers.
● Problems with behavior, thinking, reasoning, and learning: TSC can result in learning conditions such as ADHD, autism, and other mental health conditions. TSC can cause a delay in development and often leads to behavioral problems such as hyperactivity, self-harm, and struggling to connect socially.
While these conditions are common in people with TSC, not everyone with this condition will have them.
Skin-related Symptoms:
Skin-related symptoms are often the easiest way to determine if TSC is present. Skin changes often include patches of lighter skin, areas of thickened or bumpy skin, and discolored areas. These conditions include:
● Ash leaf spots: Ash leaf spots are light patches in the skin due to decreased pigment. These spots can be hard to see, so a Wood’s light (UV light) can be used to visualize these spots easily.
● Confetti marks: Confetti skin is caused by hypopigmentation (decreased melanization – the pigmentation in your skin) scattered over body regions. They are 1-3 mm in diameter (Northrup & Krueger, 2013).
● Facial, Fingernail, and Toenail fibromas: These are noncancerous tumors that develop on the skin of your face. They can form plaques if they are close enough to each other. They often appear darker than the surrounding skin, and may occur at any time during your life.
● Shagreen patches: A shagreen patch is an irregularly shaped mark on the lower back of the skin. It is made up of excess fibrous tissues and is generally on the larger side.
Changes Inside Your Body:
TSC can cause tumors to grow in other places throughout the body as well. These can include the mouth, kidney, heart, lung, or eye. These possible changes include (Tuberous Sclerosis, Mayo Clinic, 2022):
● Dental Changes: Teeth can have fibromas from lack of enamel on your teeth. These pits on the surface can appear on the gums, teeth, cheek, or tongue. They may cause cavities and bleeding due to irritation.
● Kidneys: Tumors in your kidneys can disrupt kidney function. This can lead to renal cell carcinoma, a type of kidney cancer; blood in your urine; or kidney stones. Growth in the kidneys can cause high blood pressure or bleeding, often leading to kidney failure.
● Growths in your heart (cardiac rhabdomyoma): Although highly unlikely, large tumors in the heart can disrupt blood flow leading to developmental problems. Tumors in the heart are usually the largest at birth and shrink as time goes on. This can lead to problems regarding heart rhythms.
● Growths in your lungs: Tumor development in the lungs can be severe. These tumors are more common in females and may result in coughing or trouble breathing. This can cause damage to the lung tissue and may cause a collapsed lung.
● Growths on your retinas or optic nerves: Tumor growth on the eye can affect vision, although unlikely. These tumors may appear as white patches on the retina.
Testing:
Testing for TSC is generally done through genetic testing. Genetic testing is often done to see if the TSC1 or the TSC2 gene has been mutated. Other tests include a Wood’s Lamp examination or a skin biopsy to test for skin conditions, and an MRI or EEG may be performed on the brain (Tuberous Sclerosis: What It Is).
Management and Treatment
How Is Tuberous Sclerosis Treated?
Tuberous sclerosis is a lifelong disease, but the effects are often treatable. Treatment can be provided through (Tuberous Sclerosis: What It Is):
Medications:
Depending on your symptoms and tumor location, different medications may be given. These can include medications that slow or stop tumor growth or seizure prevention medications.
Surgery:
Depending on where the tumor growth happens, surgeries may be an option. Surgery may be provided to remove certain tumors that are affecting your body. You should ask your healthcare provider if surgery is a viable option for you.
Dermatology treatments:
Most symptoms of TSC are visible and may make you stand out compared to your contemporaries. You may experience feelings of anxiety, displacement, or embarrassment. A dermatologist may be able to remove or mask the visible parts of skin complexions (Tuberous Sclerosis: What It Is).
What Can I Expect If I Have Tuberous Sclerosis? TSC can have a wide range of effects on your life, depending on the case. There are three different cases of TSC, and most will require scanning to be done every 1-2 years (Tuberous Sclerosis: What It Is):
● Mild cases: Mild cases may require medication or prescriptions but face no harm or disruption. These individuals will have the same expected lifespan as someone without TSC.
● Moderate cases: TSC may cause some disruptions for people with moderate cases, but the effects can often be treated. These individuals may have an average or slightly shorter expected lifespan.
● Severe cases: TSC may cause intellectual disabilities, Epilepsy, or other health concerns. In this case, they may not be able to live independently and may require medical care for most of their lives.
When Should I See My Healthcare Provider?
Symptoms of TSC are usually noticed at birth or during childhood. If you notice any symptoms, contact your child’s healthcare provider. If you are diagnosed with TSC, you will likely undergo regular checkups so your healthcare provider can monitor your tumors and conditions. Severe complications of TSC can be avoided. Be sure to check with your current healthcare provider if you have any more questions.
Resources
“NCI Dictionary of Cancer Terms.” National Cancer Institute, www.cancer.gov/publications/dictionaries/cancer-terms/def/subependymal-giant-cell-astr ocytoma. Accessed 27 May 2023.
Northrup, Hope, and Darcy A. Krueger. “Tuberous Sclerosis Complex Diagnostic Criteria Update: Recommendations of the 2012 International Tuberous Sclerosis Complex Consensus Conference.” Pediatric Neurology, 19 Sept. 2013, https://www.sciencedirect.com/science/article/pii/S0887899413004906.
Ranke, Felipe Mussi von, et al. “Imaging of Tuberous Sclerosis Complex: A Pictorial Review.” Radiologia Brasileira, Jan. 2017, www.ncbi.nlm.nih.gov/pmc/articles/PMC5347503/.
“Tuberous Sclerosis Complex: Medlineplus Genetics.” MedlinePlus, https://medlineplus.gov/genetics/condition/tuberous-sclerosis-complex/. Accessed 26 May 2023.
“Tuberous Sclerosis.” Mayo Clinic, 6 Dec. 2022, https://www.mayoclinic.org/diseases-conditions/tuberous-sclerosis/symptoms-causes/syc-20365 969.
“Tuberous Sclerosis: What It Is, Symptoms & Treatment.” Cleveland Clinic, my.clevelandclinic.org/health/diseases/17586-tuberous-sclerosis. Accessed 23 May 2023.
