Tuberous sclerosis complex (TSC), is a rare genetic condition in which benign (noncancerous) tumors grow in the brain and other vital organs.
The condition varies in severity depending on the location of the tumors. More severe symptoms may occur when the tumors affect the normal function of a body organ. For instance:
TSC is often diagnosed within the first year of life, but it may be diagnosed before a baby is born or take years before diagnosis is known if symptoms are mild.
TSC occurs in about 1 in 6,000 births. It affects all ethnic groups and genders equally. There is no cure for TSC. However, appropriate treatment allows many people with the condition to have very positive outcomes and lead full, productive lives.
Approximately 1 in 3 cases of TSC are caused by a genetic mutation passed on from the parent. This is a permanent DNA abnormality that exists in every cell of the body. The remaining two-thirds of TSC genetic mutations occur at random.
Half of all people with TSC will pass the condition on to their children.
Your child’s symptoms may be very subtle in the beginning. Seizures and / or white patches on the skin are often the first signs of the condition.
Nearly all children with TSC will have some symptoms related to how the brain works. Roughly 80-90% of children with TSC have epilepsy or experience generalized or partial seizures. Medicines can help lessen these symptoms.
Infantile spasms seizures may occur in about a third of children and most often occur when a child is between 3 and 10 months old. During an infantile spasm, a child’s head, abdomen, arms and legs may jerk briefly. The child may cry during and after the episodes. Infantile spasms often occur when first waking up from sleep and may occur regularly for a period of days, go away and then begin again. Medicines may provide relief from these spasms.
Tuberous sclerosis complex was named after a commonly associated brain lesion, called a cortical tuber. These non-cancer (benign) lesions usually form on the outside surface of the brain. Other types of brain lesions called nodules may occur deeper inside the brain.
The nodule brain lesions may grow in roughly 20% of those affected with TSC. Depending on their location, they may block the flow of fluid in the brain. As fluid builds up, a child may have an increase in seizures, headaches and vision problems. A medication is prescribed to shrink the nodules and reverse the symptoms.
Screening for these changes should take place regularly so that concerning growth can be addressed promptly.
Your child may have white patches on the face, body or fingernails, most of which are present at birth. The doctor may need an ultraviolet light to see these white patches.
As your child gets older, they may develop a rash on the nose and cheeks in a butterfly shape (facial angiofibroma). They may also see small skin nodules (bumps) develop around fingernails and toenails, and fibrous tissue on the forehead, neck or back.
None of these skin conditions are harmful to your child.
Lesions caused by TSC in the kidney are very common and may cause a change in kidney function. Screening for these lesions and checking kidney function over time are both part of routine TSC care.
The majority of children with TSC are born with benign heart tumors (cardiac rhabdomyomas). These tumors may show up in an ultrasound before birth or are identified in the first year of life, at which time a referral to a cardiologist is given. These tumors often reduce in size on their own as the child grows.
If a child has heart rhythm disturbances or "flutters," they usually see a cardiologist again for evaluation.
About half of all children with TSC will have retinal (eye) lesions. These rarely impact vision.
Occasionally, some section of the retina, iris or eyelashes will have little or no color / pigmentation.
The largest challenges for children with TSC and their families are developmental and behavior disorders caused by the way TSC affects the brain’s functions. Most children with tuberous sclerosis will have some degree of difficulty with learning, and roughly half of children will have one or more of the following:
Some children may have normal development and intelligence compared to other children but may still face mild learning disabilities.
Diagnosing TSC is a detailed process because the condition may impact many of the body’s systems. At first, symptoms may be considered isolated problems when, in reality, they are caused by a single condition.
During the diagnosis process, a combination of other diagnostic tests and procedures help to understand:
A genetics specialist uses their expertise to help identify specific mutations that are the cause of TSC. However, not all instances of tuberous sclerosis complex can be confirmed genetically.
Children with TSC are often seen by a multi-disciplinary team of specialists who will suggest treatment based upon your child’s specific situation. Your child may be examined and / or treated by the following specialists:
Anti-seizure medicines or surgery may help alleviate seizure symptoms.
If your child has a tumor that inhibits normal body system function, special medication called an mTOR inhibitor may be prescribed to help shrink it. Sometimes, a surgical procedure may be needed to remove a tumor.
Many children born with tuberous sclerosis complex live full and productive lives. The condition must be treated appropriately through the years, but in most cases, outcomes are very positive with normal life expectancy.
As with most genetic conditions, the long-term outlook for a diagnosed child varies widely based upon severity of the symptoms. Some children may have only mild symptoms, allowing them to live very similarly to other children. Other children with the condition may experience more severe symptoms that result in ongoing physical and mental challenges.
Early detection of TSC is very important to screen for and then promptly treat various aspects of the condition. Upon diagnosis, connecting with a TSC specialist as soon as possible for appropriate treatment recommendations and ongoing care will improve a child’s chances of leading a full and productive life.
Our Tuberous Sclerosis Clinic cares for nearly 600 patients each year, making it one of the largest centers in the world treating this complex condition.
Last Updated 06/2025
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