What Is Tuberous Sclerosis Complex?
Tuberous sclerosis (TOO-bur-iss skluh-ROE-sis) complex is a genetic condition that causes the growth of noncancerous (benign) tumors. This happens when cells grow out of control and divide more than they should. Rarely, these benign tumors can become cancerous.
The tumors caused by tuberous sclerosis complex (TSC) are called hamartomas (ham-ar-TOE-muhs). Hamartomas can grow in many parts of the body. They mostly affect the skin, brain, kidneys, heart, eyes, and lungs.
What Are the Signs & Symptoms of Tuberous Sclerosis Complex?
Tuberous sclerosis complex symptoms can range from mild to severe. The condition can affect:
- Abnormal structures. Three main types of abnormal brain structures are associated with TSC:
- cortical tubers: These benign lesions most often affect the brain's outer layer. Their abnormal cells can lead to the development of seizures.
- subependymal nodules (SEN): These are small benign collections of cells along the walls of the cerebral ventricles, the areas in the brain that contain cerebrospinal fluid (CSF).
- subependymal giant cell astrocytoma (SEGA): This is a type of benign brain tumor that can cause problems, such as blocking the flow of CSF and leading to increased brain pressure.
- Epilepsy: Seizures are one of the most common neurological symptoms in TSC, affecting about 85% of those who have it. Some infants with TSC can develop infantile spasms. Older children and adults may have different types of seizures. Many patients will go on to develop intractable epilepsy, and may be candidates for epilepsy surgery.
- TSC-associated neuropsychiatric disorder (TAND): This refers to the broad spectrum of cognitive, behavioral, and psychiatric symptoms associated with TSC, such as autism spectrum disorder, behavioral problems, intellectual disabilities, psychiatric disorders, and neuropsychological problems.
Many patients with TSC have kidney disorders at some point, such as:
- renal cysts: These are small, fluid-filled “bubbles” in the kidney. Most the time, they do not cause problems, but can lead to increased blood pressure and, rarely, kidney failure.
- renal angiomyolipoma: These benign kidney tumors can contain abnormal blood vessels that can lead to weak spots, called aneurysms. These aneurysms may burst and cause bleeding.
- renal cell carcinoma: Although this is very rare, it's important to have frequent visits with a kidney specialist, who can watch for it.
Hamartomas in the heart (called cardiac rhabdomyomas) most often affect the ventricular and septal walls. They're most common in newborns and babies who have TSC., and usually get smaller as a child grows. But they can block blood flow or change the heart's rhythm, causing heart failure.
If hamartomas happen on the retina, they sometimes can affect vision.
Hamartomas in the lungs can cause coughing, trouble breathing, a buildup of fluid around the lung, and/or chest pain. These affect the lungs more often in females, and don't cause problems until adulthood. Sometimes, they cause no symptoms.
Patients with TSC may have small pits on their teeth, call enamel pits, that can be easy places for tooth decay to start. This is different from cavities — these pits are areas where enamel did not form, so food can build up there and start a cavity. Small, harmless areas of growth on the gums (called gingival fibromas) also can happen. Often, these don't need any treatment unless they cause irritation or bleeding.
What Causes Tuberous Sclerosis Complex?
Tuberous sclerosis can be inherited or happen randomly:
Inherited. Most cases of tuberous sclerosis are due to a genetic mutation (change) in one of two genes, TSC1 or TSC2. A baby will be born with tuberous sclerosis if the child inherits a TSC gene from either parent.
Randomly. In other cases, both parents of a child with tuberous sclerosis have normal DNA (no TSC gene). This is called a new or spontaneous mutation.
How Is Tuberous Sclerosis Complex Diagnosed?
Early signs that a child has tuberous sclerosis often include:
- seizures (uncontrolled shaking of the body)
- developmental delay (walking, talking, or other new skills happen later than in most children)
Most cases of TSC usually are found when a child sees a doctor after a seizure. Doctors usually diagnose it based on skin changes and other symptoms. They also might order these tests:
Children who have very mild symptoms might not be diagnosed until the teen years or later.
If a pregnant woman has tuberous sclerosis or a TSC gene runs in the family, prenatal tests might show whether the unborn baby has the TSC gene. Sometimes, doctors suspect TSC before birth if an ultrasound shows the baby has cardiac rhabdomyoma(s).
How Is Tuberous Sclerosis Complex Treated?
So far, there is no cure for TSC. But many of its symptoms get better with treatment. Tuberous sclerosis complex is a lifelong condition that can affect one or many parts of the body. So, kids who have it can need care from many specialists, such as:
- neurologists for brain-related symptoms
- nephrologists or urologists for kidney problems
- dermatologists for skin issues
- pulmonologists for lung problems
- ophthalmologists for eye problems
- psychiatrists or psychologists for learning, behavior, or emotional issues
- geneticists for genetic testing
Depending on where the tumors are and if they cause problems:
- A surgeon can remove tumors in the heart, brain, or kidney.
- Doctors may prescribe a medicine that can shrink the tumors.
- Someone with severe kidney problems might need dialysis (use of an artificial kidney machine) or a kidney transplant.
- Physical therapy, occupational therapy, speech therapy, and behavioral therapy can help with developmental delay and behavior problems.
Medicines can help treat:
What Else Should I Know?
Ongoing, regular medical care for tuberous sclerosis complex is important. Doctors will watch for tumor growth and see how treatment is working. This includes doing MRI scans of the head, ultrasound or MRI scans of the belly, and echocardiograms every 1–3 years.
Early diagnosis can help most kids with TSC get the care they need to lead active, independent lives.
If your child has tuberous sclerosis complex, you don't have to go it alone. Look for an online or local support group, like the Tuberous Sclerosis Alliance, where you can connect with other families dealing with TSC. They can share what works for them and be a lot of help if you feel overwhelmed. Ask your child's doctor for recommendations.