Tuberous sclerosis complex is a genetic disorder that causes benign, or nonmalignant, tumors to form in many different organs in the body. The brain, heart, kidneys, skin, lungs and eyes are some of the more critical locations that these tumors appear. When tumors form in the brain they can cause seizures, developmental delays, intellectual and mental disorders. TSC is also considered a leading cause of epilepsy and autism. Thanks to advancements in diagnosis and highly specialized treatment, children and adults with TSC enjoy happy, healthy lives.
Every day, at least two children are born with tuberous sclerosis complex, that’s approximately one in every 6,000 births. It is estimated that some 1 million people worldwide have been diagnosed with this disorder with nearly half of those cases right here in U.S.
TSC is a genetic disease, but it isn't always inherited. Only about one-third of TSC cases are inherited. However, if one or both parents have TSC, their children have a 50% chance of being born with TSC. Most cases of TSC are caused by a spontaneous genetic mutation that occurs during conception or in the early weeks of the embryo’s development.
Because TSC can manifest in so many different ways, diagnosis is generally made when physicians identify any two major features of TSC in one individual. One major feature is cardiac rhabdomyoma, an abnormal growth in the heart muscle generally found in young children and sometimes found by ultrasound examination during pregnancy. Other major features include specific abnormal skin growths or skin pigmentation, specific non-malignant tumors or growths such as subependymal nodules or subependymal giant cell astrocytomas (SEGAs) in the brain, lymphangioleiomyomatosis (LAM) in the lungs, angiomyolipomas in the kidney(s), and tubers in the brain or hamartomas in the eye. Also, there are other minor features of TSC that might be diagnostic if found with a major feature in the same person. TSC can also be diagnosed by genetic testing.
Because of the very complex nature of this disorder, your child’s testing and diagnostics team will likely include specialists in:
Depending on the extent of your child’s disease and the location of any tumors, other specialists may be consulted as well.
Early diagnosis and intervention can help overcome developmental delays. Data show that early seizure control in children can improve learning as compared to children without good seizure control. Advancements in research continue to bring new and improved therapeutic options. Some anti-seizure drugs can be effective in individuals with TSC. When drug treatment fails to adequately control seizures, technology can help identify the exact portions of the brain stimulating seizures and creating new therapies to help control seizures.
For tumors in the brain, surgery is sometimes used to permanently remove tumors that are relatively few in number and easily accessible by the surgeon. In other cases, drug treatment may be used to shrink brain tumors. In the fall of 2010, the FDA approved the first drug with an indication specifically for TSC to treat a type of brain tumor known as subependymal giant cell astrocytomas (SEGAs). In 2012, the same drug was approved to treat growing angiomyolipomas, a type of kidney tumor in TSC.
Major advancements in treatments such as these require clinical studies to test the effectiveness of experimental drugs, surgery, or other interventions in people with TSC. Because the TSC community is in vital need of new treatments, individuals with TSC frequently volunteer to participate in cutting-edge clinical studies. Some ongoing clinical studies in TSC include testing the effects of drug treatment on neurocognitive function, testing a new combination drug treatment for LAM, finding biomarkers to identify infants at high risk of developing autism or infantile spasms, and testing a topical drug treatment of facial angiofibromas. Thanks to volunteers in these and other studies, every new day brings us one step closer to finding improved treatments for TSC.
Most people with TSC will live a normal life span. There can be complications in some organs such as the kidneys and brain that can lead to severe difficulties and even death if left untreated. To reduce these dangers, people with TSC should be monitored throughout their life by their physician for potential complications. Thanks to research findings and improved medical therapies, people with tuberous sclerosis complex are experiencing better health care than ever before. But more research is needed until we find a cure.
The growth of tumors resulting from tuberous sclerosis complex is not as severely unregulated as in cancer, but these tumors may still cause serious problems. Tumors that grow in the brain can block the flow of cerebral spinal fluid in the spaces (ventricles) in the brain. This can lead to behavioral changes, nausea, headaches or a number of other symptoms.
In the heart, the tumors are usually at their largest at birth and then decrease in size as the individual gets older. These heart tumors, called cardiac rhabdomyomas, can cause problems at birth if they are blocking the flow of blood or causing severe arrhythmia.
Tumors in the eyes are not as common, but can present problems if they grow and block too much of the retina.
Tumors in the kidney (renal angiomyolipomas) can become so large they eventually disrupt normal kidney function or begin to bleed internally. In the past, kidney failure was almost inevitable. Today, doctors can use drug therapy to shrink angiomyolipomas or can destroy individual tumors by embolization before they get too large and compromise healthy kidney tissue. In cases of severe pain or bleeding, angiomyolipomas can be removed by surgery. Renal cell carcinoma is very rare in TSC.