Tuberous sclerosis is a rare genetic multisystemic disorder that typically appears shortly after birth. The disorder can cause a wide variety of potential signs and symptoms and is associated with the formation of benign (non-cancerous) tumors in various organ systems of the body. You can find more information below.
What is tuberous sclerosis?
Tuberous sclerosis is a genetic disease characterized by the growth of multiple noncancerous (benign) tumors in many parts of the body . These tumors can occur in the skin, brain, kidneys and other organs, in some cases leading to significant health problems. Tuberous sclerosis causes developmental problems and its symptoms vary from person to person.
Nearly all affected people have skin abnormalities, including unusual patches of light-colored skin, raised and thickened skin areas, and growths under the nails. Tumors in the face , called facial angiofibromas , are also common in childhood.
Tuberous sclerosis usually affects the brain; causes seizures, behavioral problems such as hyperactivity and aggression, and intellectual disability or learning problems. Some affected children have the characteristic features of autism , a developmental disorder that affects communication and social interaction . Benign brain tumors can also develop in people with tuberous sclerosis, and in some cases, these tumors can cause serious or life-threatening complications.
Kidney tumors are common in people with tuberous sclerosis; These growths can cause serious kidney problems. In some cases, it can be life threatening. In addition, tumors can develop in the heart, lungs, and light-sensitive tissue at the back of the eye (retina).
What is the incidence?
Tuberous sclerosis is rare, affecting around 1 in 6,000 people.
Causes of tuberous sclerosis
Mutations in the TSC1 or TSC2 gene can cause tuberous sclerosis. The TSC1 and TSC2 genes provide instructions for making proteins called hamartin and tuberin. Inside cells, these two proteins likely work together to help regulate cell growth and size. Proteins normally act as tumor suppressors, preventing cells from growing and dividing too quickly or uncontrollably.
People with tuberous sclerosis are born with a mutated copy of the TSC1 or TSC2 gene. This mutation prevents the cell from making functional hamartin or tuberin from the altered copy of the gene. However, enough protein is usually produced from the other normal copy of the gene to effectively regulate cell growth. For some types of tumors to develop, a second mutation involving the other copy of the TSC1 or TSC2 gene must occur in certain cells during a person’s lifetime.
When both copies of the TSC1 gene are mutated in a particular cell, that cell cannot produce any functional hamartin; Cells with two altered copies of the TSC2 gene are unable to produce any functional tuberin. The loss of these proteins allows the cell to grow and divide uncontrollably to form a tumor. In people with tuberous sclerosis, a second TSC1 or SC2 mutation typically occurs in more than one cell over the lifetime of an affected person. Loss of hamartin or tuberin in different cell types leads to the growth of tumors in many different organs and tissues.
Tuberous sclerosis symptoms
Tuberous sclerosis symptoms are caused by non-cancerous growths (benign tumors) anywhere in the body, most commonly the brain, eyes, kidneys, heart, lungs, and skin. Symptoms can range from mild to severe, depending on the size or location of the overgrowth.
While symptoms are unique to each person with tuberous sclerosis, they can include:
- Skin abnormalities: Most people with tuberous sclerosis have patches of light skin, may develop small, harmless, thickened, smooth skin or reddish bumps under or around the nails.
- Seizures: Enlargement in the brain may be associated with seizures, which may be the first sign of tuberous sclerosis. In young children, a common type of seizure called infantile spasm presents as recurrent spasms of the head and legs.
- Cognitive disabilities: Tuberous sclerosis can be associated with developmental delays and sometimes with intellectual disability or learning disabilities. Mental health disorders such as autism spectrum disorder or attention deficit hyperactivity disorder (ADHD) can also occur.
- Behavior problems: Common behavioral problems may include hyperactivity, self-harm or aggression, or social and emotional adjustment issues.
- Kidney problems: Most people with tuberous sclerosis develop noncancerous growths on their kidneys and may develop more growths as they age.
- Heart problems: In people with tuberous sclerosis, the enlargement of the heart usually occurs at birth and gets smaller as the child grows.
- Lung problems: Enlargements that develop in the lungs can cause coughing and shortness of breath, especially with physical activity or exercise. These benign lung tumors are more common in women than men.
- Eye abnormalities: The growths may appear as white patches on the light-sensitive tissue (retina) at the back of the eye. These noncancerous growths do not always obstruct vision.
When should you see a doctor?
Symptoms of tuberous sclerosis may be recognized at birth, or the first symptoms may become evident in childhood or even years later in adulthood.
If you are concerned about your child’s development or notice any of the symptoms described above, you should contact your child’s doctor.
Tuberous sclerosis diagnosis
Depending on your child’s symptoms, you may need to see a neurologist, cardiologist, ophthalmologist, dermatologist, nephrologist, and other specialists.
Your child’s doctors will perform a physical exam, discuss symptoms and family health history, and look for typical growths (benign tumors) commonly associated with tuberous sclerosis. They will also likely order a variety of tests, including genetic testing, to diagnose tuberous sclerosis and identify related problems.
If your child has had a seizure, the diagnostic test will likely be an electroencephalogram . This test records electrical activity in the brain and can help you determine what is causing your child’s seizures.
Brain, lungs, kidneys and liver assessment
Diagnostic tests to detect growths or tumors in the body will likely include:
- Magnetic resonance imaging: Magnetic resonance imaging uses a magnetic field and radio waves to create detailed images of the brain or other parts of the body.
- Computed tomography scan: A CT scan produces cross-sectional images, and sometimes 3D images, of the brain or other parts of the body.
- Ultrasound: Also called sonography, this test uses high-frequency sound waves to create images of certain body parts, such as the kidneys.
Diagnostic tests to determine if your child’s heart is affected will likely include:
- Echocardiogram: This test uses sound waves to produce images of the heart.
- Electrocardiogram: This test records the electrical activity of the heart.
A light and magnifying lens are used to examine the inside of the eye, including the retina.
Developmental or psychiatric assessment
If necessary, based on routine screening, an evaluation with a psychiatrist, psychologist, or other mental health professional can identify developmental or mental disabilities, educational or social problems, behavioral or emotional disorders.
Screening and genetic testing
If a child is diagnosed with tuberous sclerosis and no other family member has the disease, both parents may consider screening for tuberous sclerosis.
Parents may also consider genetic testing to confirm a diagnosis of tuberous sclerosis in their child and to understand the risk for their other children and future children.
Adults with tuberous sclerosis may consider genetic counseling before considering having children.
Tuberous sclerosis treatment
Although there is no clear cure for tuberous sclerosis, treatment can help manage specific symptoms such as:
- Medication: Anti-seizure medications may be prescribed to control seizures. Other medications can help manage heart arrhythmias, behavior problems, or other symptoms. A medicine called everolimus may be used to treat certain brain and kidney growths that cannot be surgically removed. A topical ointment form of a drug called sirolimus can help treat acne-like skin growths.
- Surgery: If the growth affects the function of a particular organ, such as the kidney or heart, it can be surgically removed. Sometimes surgery also helps control seizures caused by brain growths that don’t respond to medication. Surgical procedures such as dermabrasion or laser therapy can improve the appearance of skin growths.
- Various types of treatment: Early intervention services such as occupational, physical, or speech therapy can help children with tuberous sclerosis with special needs in these areas improve their ability to manage daily tasks and activities.
- Education and vocational services: Early intervention and special needs services can help children with developmental delays and behavior problems adapt to the classroom so they can reach their full potential. When necessary, social, vocational and rehabilitation services can continue throughout life.
- Psychiatric and behavioral management: Talking to a mental health professional can help children accept and adapt to having this disorder. A mental health professional can also help address behavioral, social, or emotional issues and suggest resources.
Remember, your doctor will decide how to take the medicine.
Tuberous sclerosis is a lifelong condition that requires careful monitoring and follow-up because many symptoms can take years to develop. A regular program of follow-up monitoring throughout life may include tests similar to those performed at diagnosis. Identifying problems early can help prevent complications.
Tuberous sclerosis complications
Depending on where and size of noncancerous growths (benign tumors) develop, they can cause serious or life-threatening complications in people with tuberous sclerosis. Here are some examples of complications:
- Excess fluid in and around the brain: A type of brain enlargement can block the flow of cerebrospinal fluid within the brain. This blockage can cause fluid to build up in the cavities (ventricles) deep in the brain, a condition called hydrocephalus . Various symptoms include unexpected head size, nausea, headache, and behavioral changes.
- Heart complications: Enlargements in the heart, usually in infants, can block blood flow or cause problems with heart rhythm ( dysrhythmia ).
- Kidney damage: The enlargement in the kidney can be larger than normal and potentially cause serious – even life-threatening – kidney problems. An enlarged kidney can cause high blood pressure, bleeding, or kidney failure. Rarely, kidney growths can be cancerous.
- Lung failure: Enlargement in the lungs can affect lung function, causing collapse or fluid in the lungs.
- Increased risk of cancerous (malignant) tumors: Tuberous sclerosis is associated with an increased risk of developing malignant tumors in the kidneys and brain.