Tuberous sclerosis (TSC)
If your child has just been diagnosed with tuberous sclerosis, or if his doctor is recommending that he be evaluated, it’s natural for you to want to learn as much as possible about the condition. We hope the information in these pages is helpful to you, and when you meet with our experts, we can explain your child’s condition and the treatment plan fully.
Tuberous sclerosis complex (also called tuberous sclerosis, TS or TSC) is a genetic condition that affects multiple systems in the body. The symptoms usually appear before a child is 6 months old. Each person who has TSC is affected in a different way: In some children, the disease is very mild, whereas for others, it can involve life-threatening complications.
It’s estimate that TSC affects about 50,000 people in the United States and one million worldwide; one in 6,000 children are born with the disease. It affects all ethnic groups, and girls and boys have an equal chance of having the disease.
The hallmark of TSC is a variety of benign (non-cancerous) tumors in the brain. The name “tuberous sclerosis” comes from one of these types of abnormal cell structures, called cortical tubers. Other common complications of TSC are:
- Tumors and other abnormal tissue can grow in many places, including the brain, skin, heart, eyes, kidneys and lungs. Almost all of these lesions are benign (not cancerous), but they can cause a variety of different problems.
- Many children who have tuberous sclerosis develop epilepsy. Babies may have infantile spasms, and older children can have other types of seizures
- Children with TSC often have some type of intellectual disabilityor developmental or behavioral disorder, including autism spectrum disorders.
Learn more about the complications of TSC under Symptoms
TSC is one of several conditions that are called neurocutaneous syndromes. All of these disorders are genetic conditions that cause tumors and other types of abnormal tissue to grow in the brain, skin and other organs. The other neurocutaneous syndromes are:
TSC is a genetic condition, but it’s often not inherited
TSC is a genetic condition, meaning it’s caused by a DNA change (mutation). A change in either of two genes—called TSC1 and TSC2—can cause tuberous sclerosis. In about 80 percent of people who have TSC, genetic testing can detect a mutation in one of these genes.
Currently, there’s no clear connection between which TSC-causing mutation a person has and his particular kind of symptoms. So even if two people in the same family have the same mutation, their TSC symptoms may be very different.
Since 20 percent of people with TSC don’t have an identifiable mutation, researchers are looking for additional DNA changes that may cause the disease. Read more about the search for new DNA changes that can cause TSC under Research & Innovation
TSC is an autosomal dominant genetic condition. This means that:
- Girls and boys have an equal risk of having the condition.
- A mutation in only one copy of a gene causes TSC. A child can inherit the condition if either parent has it.
- A person who has TSC has a 50 percent chance of passing the condition on to each child.
About a third of children with TSC inherited the genetic condition from a parent. However, for two-thirds of children with TSC, the condition is “spontaneous,” meaning that a child’s DNA change is the first instance of that change in his family—he didn’t inherit it.
Sometimes, a child with TSC does have a parent who also has TSC but the parent doesn’t know it because her symptoms have been very mild. So if your child is diagnosed with TSC, you may need to be examined and have genetic testing done, as well.
If you have a child with TSC, there is also an increased likelihood that your other children will have the condition. In some cases, if the family of a child with TSC has another pregnancy, we may refer them to the Advanced Fetal Care Center for advanced ultrasound screening.
We know that going through genetic testing and the diagnostic process can be difficult for families, and we’ll be here for you every step of the way. Our Multi-Disciplinary Tuberous Sclerosis Program is managed by a genetic counselor who is experienced in working with families like yours and is available to talk with you and answer any questions you have.
TSC affects each child differently
The symptoms of TSC vary greatly from child to child. In some children, the disease involves severe complications in multiple organ systems, whereas in others, it may be so mild that they don’t even know they have the disease.
Each child’s health is affected to various degrees depending on his particular complications. It’s important for your child to be monitored closely so that if complications do come up, they can be treated early on. The good news is that most children with TSC who are under an experienced physician’s care can expect to live active and productive lives with normal life expectancies.
Some of the symptoms of TSC, such as white skin patches, are present at birth. So in many cases, children are diagnosed with TSC as infants. Sometimes, the benign heart tumors characteristic of TSC are detected even before birth, in a prenatal ultrasound. On the other hand, some people have such mild symptoms that they aren’t diagnosed until adulthood.
The most common features of tuberous sclerosis complex (TSC) are:
- benign tumors and other abnormal tissue (collectively referred to as “lesions”) in many organ systems, including the brain, skin, heart, eyes, kidneys and lungs
- learning disabilities and developmental and behavioral disorders, including autism spectrum disorders
Every person with TSC doesn’t experience all of these complications, and a person’s symptoms can change over time. The different complications of TSC are outlined in more detail below.
Tumors in the brain
In about 95 percent of affected children, their brains are affected in some way. Most children have some type of benign (non-cancerous) tumor:
- Cortical tubers are hard, knobby lesions made up of a collection of abnormally sized neurons and supporting cells called glia. The tubers are most often found in the cerebral cortex—the outermost layer of the brain, commonly called the “gray matter.” The number, size and location of the tubers vary greatly and are thought to be what cause the seizures.
- Subependymal nodules develop along ventricles in the brain, the structures holding the cerebrospinal fluid (CSF) that surrounds the brain. These lesions have the shape of wax dripping from a candle, so they used to be referred to as “candle guttering.” They are benign and generally don’t cause any problems; however, in 5 to 10 percent of cases, they degenerate into subependymal giant cell astrocytomas (described below).
- Subependymal giant cell astrocytomas (SEGAs) are lesions that can grow and block the circulation of CSF around the brain and cause hydrocephalus. The buildup of CSF can cause a dangerous increase of pressure inside the head, so this condition requires neurosurgery to reduce the pressure and drain the extra CSF.
Seizures and epilepsy
About a third of the time, the epilepsy starts out as a type of seizure called infantile spasms, usually when a child is about 4 to 6 months old. (Infantile spasms usually don’t happen before a child is two weeks old or after 18 months.) They involve brief, but often repetitive, muscle contractions and movement in the head, trunk, arms and legs.
- The spasms often happen in clusters.
- Children usually cry when these spells happen. Often, they look like they have colic or an abdominal problem.
- The spasms often happen when a child is waking up.
As a child with TSC gets older, he may develop partial or generalized seizures. See Types on our seizures webpage to learn more about the different types of seizures.)
Neurodevelopmental and behavioral disorders
Children with TSC are at an increased risk of having neurodevelopmental and behavioral disorders.
- About half of children with TSC have a learning disability. Many children who have normal intelligence will still experience some type of learning disability.
- Many children with TSC have a developmental or behavioral disorder. These include:
Autism spectrum disorders (ASDs) are especially common among children with TSC; it’s been estimated that up to 60 percent of children with TSC develop an ASD. ASDs are developmental conditions that may involve difficulties communicating and interacting with other people, along with unusual, restricted or repetitive behaviors. They include three specific diagnoses: autism, Asperger’s syndrome and pervasive developmental disorder – not otherwise specified (PDD-NOS).
Experts don’t fully understand why children with TSC often develop ASDs and other developmental and behavioral conditions, and this is an intense area of investigation. But we do know that early diagnosis and therapy can be enormously helpful to children with these conditions. So it’s important to talk with your doctor if you have any concerns about your child’s development or behavior.
Almost all children with TSC have some type of lesions on their skin.
The earliest sign of TSC may be white skin patches (hypomelanotic macules) on your child’s body, since babies are born with them.
- As your child gets older, a facial rash with a characteristic butterfly distribution (facial angiofibroma) may appear across his nose and cheeks.
- During the teenage years or later, small bumps may form under his fingernails or toenails (ungual fibromas). Your child might also have a shagreen patch, an area of skin that is thickened and dimpled like an orange peel, on his lower back.
None of the skin lesions are harmful. However, the facial angiofibromas can be distressing because of their prominent location. Look under Treatment & Care to see the variety of treatmentsavailable for this rash.
Children with TSC are often born with benign (non-cancerous) heart tumors called cardiac rhabdomyomas. It’s estimated that as many as two-thirds of people with TSC have these tumors. They usually don’t cause any symptoms, and they often regress on their own, either shrinking or completely disappearing as children get older.
Cardiac rhabdomyomas, like the white skin patches, are often an early sign that a child may have TSC. They’re usually detected in newborns, but they may also be picked up during a routine prenatal ultrasound. Infants who have cardiac rhabdomyomas have a 50 percent chance of having TSC; the other 50 percent have just the cardiac rhabdomyomas.
Although the tumors are benign and usually don’t cause any problems, they sometimes block blood flow in the heart and cause an abnormal heart rhythm (arrhythmia). Occasionally, this needs to be treated with medications or surgery.
TSC affects children’s eyes more than half of the time.
- Many children with TSC have lesions on the retina called hamartomas. Most of these lesions stay dormant, so they don’t usually cause a loss in vision.
- White patches (“hypopigmented” areas)—similar to the white skin patches—sometimes appear on the retina, iris, or even eyelashes. These aren’t harmful and don’t require treatment.
Most children who have TSC have some type of lesion in their kidneys. Usually, these lesions grow very slowly and don’t cause problems during childhood.
- Benign kidney tumors called renal angiomyolipomas account for most of the kidney abnormalities seen in children with TSC. Angiomyolipomas are made up of blood vessels, muscle and fat. They usually grow very slowly and aren’t problematic before a child reaches young adulthood. By the time a person with TSC is in his 20s, angiomyolipomas may bleed and can also cause lower back pain.
- Simple cystsaccount for 25 percent of the kidney abnormalities seen in people with TSC. They can appear or disappear at any time. If there are multiple or large renal cysts, they can damage the kidneys.
- Renal cell carcinomais the only type of malignancy (cancer) associated with TSC. These tumors are rare, especially in children.
In addition to these different types of kidney lesions, about 70 to 80 percent of people with TSC develop other abnormalities in their kidneys, but these usually don’t cause any symptoms, especially in children.
Even though the kidney lesions that are associated with TSC generally don’t cause symptoms or require treatment during childhood, it’s important for your child to be monitored by ultrasound in order to catch any problems that may develop.
Lesions can also develop in the lungs, although this has been seen primarily in women over 30 and is quite rare (1 percent of women with TSC).
The lung (pulmonary) lesions seen in women with TSC include pulmonary cysts and lymphangioleiomyomatosis (LAM). These rare lesions sometimes cause severe lung problems. The first symptoms of these lesions may be shortness of breath, coughing, coughing up blood or spontaneous lung collapse.
Q: What is tuberous sclerosis?
A: Tuberous sclerosis complex (also commonly referred to as tuberous sclerosis, TS and TSC) is a condition that affects multiple systems in a child’s body. It can cause tumors and other abnormal tissue to grow in many organs, including the brain, skin, heart, eyes, kidneys and lungs. Almost all of these lesions are benign (not cancerous), but they can cause a variety of problems. Many children with TSC develop epilepsy, a condition in which a child has unprovoked seizures. Symptoms of TSC usually appear before a child is 6 months old.
Children with TSC often have some type of developmental delay or behavioral problem. Many children are diagnosed with an autism spectrum disorder
Q: How can the disease cause all of those different complications?
A: TSC is caused by a change (mutation) in either of two genes. Scientists believe that these genes work together to suppress abnormal growth of cells. So when a person has an altered copy of one of the genes, tumors and other abnormal tissues are allowed to grow in a number of different organs. It appears that these genes also affect how brain cells grow and connect with each other, which may be why children with the condition also can have developmental and behavioral difficulties and seizures.
Q: Do all children with TSC have all of those problems?
A: No.Each person who has TSC is affected in a different way. In some children, the disease is very mild, whereas for others, it can involve life-threatening complications. A person can also have very different symptoms at different times in their lives.
Q: How is TSC diagnosed?
A: TSC can involve many different symptoms, many of which also occur in children who don’t have TSC. So a doctor has to look for a group of features in order to make the diagnosis. Your child’s medical team may perform a number of different tests including a painless skin examination using a Wood’s lamp, brain imaging scans such as MRI, an echocardiogram, kidney ultrasound and an eye exam. Genetic testing is also an important part of making the diagnosis.
TSC is often diagnosed in infants, since some of the symptoms, such as white skin patches, are present at birth. Sometimes, heart tumors are detected by prenatal ultrasound, which can indicate that a child may have TSC. On the other hand, some people who are very mildly affected by TSC are not diagnosed until adulthood; in fact, experts believe that some people who have TSC are never diagnosed.
Q: How did my child get this disease?
A: TSC is a genetic condition, meaning it’s caused by a DNA change (mutation). In most cases, the condition is “spontaneous,” meaning that a child with TSC is the first person in his family to have the disease, because he has a new DNA change. About a third of children with TSC inherited it from a parent.
In either case, it’s important to remember that TSC is simply caused by changes in DNA; your child’s disease is not your fault.
Q: Is there a cure? What is the long-term outlook for a child with TSC?
A: Unfortunately, there is no cure for TSC yet. But there are effective treatments for many of the symptoms. The prognosis for a child with TSC varies depending on his particular complications, but most children with TSC who are under an experienced physician’s care can expect to live active and productive lives and have a normal life expectancy.
Many of the complications of TSC can be managed effectively if they’re caught and treated early. So it’s important for your child to be monitored throughout his life. Our tuberous sclerosis specialists at Children’s work closely with your family to stay on the lookout for any symptoms that may come up.
Q: Will my child have developmental problems or an intellectual disability?
A: There’s no simple answer, since different children are affected very differently. Many children with TSC do have some type of developmental delay, learning disability or behavioral problems. Autism spectrum disorders (ASDs) are common among children with TSC.
Early diagnosis and therapy can be enormously helpful to children with developmental difficulties, so your child’s medical team will watch his development closely. Talk with your doctor if you have any concerns about your child’s development or behavior.
Q: How will this condition affect my child when he becomes an adult?
A: TSC can affect people in different ways at different times in their lives. Some of the symptoms that can affect your child early on may resolve as he grows up. For example, children’s epilepsyoften resolves as they grow up, and the heart tumors characteristic of TSC usually regress on their own, either shrinking or completely disappearing as children get older. On the other hand, other complications, such as kidney tumors, occasionally cause serious problems that require treatment in adulthood. So it’s important for your child to be monitored closely not only during childhood but throughout his life.
Q: How common is TSC?
A: It’s estimated that TSC affects about 50,000 people in the United States and one million worldwide; one in 6,000 children are born with the disease. It affects all ethnic groups, and girls and boys have an equal chance of having the disease.
Q: Is there research going on to learn more about the disease and find better ways to treat it?
A: Yes. In particular, some researchers are optimistic about the drug rapamycin. Laboratory experiments and clinical studies give reason to hope that this medication may be able to reverse symptoms of TSC, but a lot still needs to be learned. Our tuberous sclerosis team is playing a major role in these efforts. Visit Research & Innovation to find out more about the TSC research going on at Children’s.
Questions to ask your doctor
You and your family are a central part of your child’s care team—not simply recipients of care. We’ll rely on you to share your observations and ideas about your child’s health with us, and we want to make sure that you, in turn, get answers to your questions and understand our recommendations and any treatment options we may present to you.
If you’re coming to Children’s Hospital Boston because your doctor suspects that your child may have tuberous sclerosis or he’s just been diagnosed, you probably have a lot of questions and fears on your mind. But at the appointment, it can be easy to forget the questions you wanted to ask. It’s often helpful to write them down ahead of time so that you can leave the appointment feeling like you have the information you need. Don’t be afraid to ask about anything you’re concerned or wondering about.
Some of the questions you may want to ask include:
- How did you arrive at the diagnosis of tuberous sclerosis?
- Does my child need any further testing?
- What is tuberous sclerosis? How serious is it?
- What may have caused this condition? Are our other children at risk of having it? Do we need to be evaluated ourselves?
- What kind of testing and care will my child need to have in the future?
- What symptoms do we need to watch for? What should we do if they happen?
- Does my child need behavioral therapies? How can they help?
- How can I access those therapies? Is my child eligible for government-sponsored early intervention services?
- When does my child need to see you again?
Tell your child’s doctor about any care your child is receiving elsewhere or research studies you’re participating in. That will help ensure that your child’s care is well coordinated. If you’re thinking about starting a medication, herbal therapy or vitamin supplement or if you’d like to try a special diet, be sure to discuss it with your child’s doctor first, since some of these may not be safe for your child. Talking with your child’s doctor first can help to avoid complications.