What is Tuberous Sclerosis (TSC)?
Tuberous sclerosis, also called 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:
- Tumors blocking the flow of fluid in the brain
- Tumors blocking kidney function
- Tumors affecting vision
Tuberous sclerosis is often diagnosed within the first year of life but may take years if symptoms are mild.
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.
How Common is Tuberous Sclerosis?Tuberous sclerosis occurs in about one in 6,000 births. It affects all ethnic groups and both genders equally.
What Causes Tuberous Sclerosis?
Approximately one in three 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 tuberous sclerosis will pass the condition on to their children.
Symptoms and Associated Conditions
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.
Seizures and Epilepsy
Nearly all children with tuberous sclerosis will have some issues with the brain. Roughly 80-90% of children with tuberous sclerosis have epilepsy or experience generalized or partial seizures. Medicines can help lessen these symptoms.
Infantile spasms occur in about a third of children and most often occur when a child is between three and ten 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.
Lesions in the Brain
Tuberous sclerosis 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 may develop deeper inside the brain.
Brain lesions grow in roughly 20% of patients. Depending on the location, they may block the flow of fluid in the brain. As fluid builds up, a child may have headaches and vision problems.
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.
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 placed. These tumors often reduce in size on their own as the child grows.
If a child has heart rhythm disturbances or ‘flutters’, they are again referred to a cardiologist for evaluation.
About half of all children with TSC will have retinal (eye) lesions, which may present as inflammation of the retina or benign tumors. These rarely impact vision.
Occasionally some section of the retina, iris or eyelashes will have little or no color / pigmentation.
Developmental and Behavioral Symptoms
Some of the largest challenges for children with TSC and their families are developmental and behavior disorders caused by brain function impairment. While nearly all children with tuberous sclerosis will face a learning disability, roughly half of children will have one or more of the following:
- Autism spectrum disorder (ASD)
- Attention deficit hyperactivity disorder (ADHD)
- Obsessive-compulsive disorder
- Aggression, sudden rage or self-harming behavior
Some children may have normal development and intelligence compared to other children but may still face mild learning disabilities.
Diagnosing tuberous sclerosis can be a complex process because the condition impacts 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:
- Causes of seizures: Your child will likely have an electroencephalogram (EEG) to record electrical activity in the brain. A neurologist will pinpoint abnormalities that may cause seizures.
- Location(s) of tumors / growths: Testing may include magnetic resonance imaging (MRI), a computerized tomography (CT) scan and / or ultrasound to locate any abnormal growths.
- Impacts on the heart: Your child will have an echocardiogram to view images of the heart and an electrocardiogram (ECG or EKG) to monitor electrical activity of the heart. This will tell whether the heart is affected by the condition.
- Genetic mutations: A small sample of your child’s blood will be sent to a genetic testing lab to identify gene mutations linked with tuberous sclerosis. Test results will allow specialists to verify diagnosis.
In many cases, tuberous sclerosis is ultimately diagnosed by a geneticist who is trained to identify very specific gene mutations tied to the condition. However, not all instances of tuberous sclerosis 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:
- Dermatologist or Plastic Surgeon
- Developmental / Behavioral Specialists
- Social Worker
- Genetics Counselor
Anti-seizure medicines or surgery may help alleviate seizure symptoms.
If your child suffers from a tumor that inhibits normal body system function, your surgeon may recommend removal of the tumor. Removal of a tumor may be non-invasive or require open surgery depending on the location of the tumor.
Many children born with tuberous sclerosis 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 tuberous sclerosis is very important to slow or halt progression of the condition. Upon diagnosis, we recommend connecting with a TSC specialist as soon as possible for appropriate treatment recommendations and ongoing care to improve your child’s chances of leading a full and productive life.