What is Tuberous Sclerosis (TS)?
Tuberous sclerosis, also known as tuberous sclerosis complex, is a rare genetic condition that causes mainly non-cancerous (benign) tumours to develop in different parts of the body.The tumours most often affect the brain, skin, kidneys, heart, eyes and lungs.Tuberous sclerosis is present from birth, although it may not cause obvious problems immediately
Sclerosis means “hardening of tissue,” and tubers are root-shaped growths.
TS can be inherited or caused by spontaneous gene mutation. Some people only have mild symptoms, while others experience:
- developmental delay
- intellectual disability
- skin abnormalities
This disorder can be present at birth, but symptoms may be mild at first, taking years to develop fully.
There’s no known cure for TS, but most people can expect to have a normal lifespan. Treatments are targeted at individual symptoms, and careful monitoring by your doctor is advised
Prevalence of Tuberous Sclerosis
Approximately 1 million people have been diagnosed with TS around the world, and according to the Tuberous Sclerosis Alliance (TSA), there are about 50,000 cases in the United States. The condition is very difficult to recognize and diagnose, so the actual number of cases could be higher.
The TSA also reports that approximately one-third of cases are inherited, and two-thirds are thought to occur from spontaneous genetic mutation. If one parent has TS, their child has a 50 percent chance of inheriting it.
Genetics of Tuberous Sclerosis
Scientists have identified two genes called TSC1 and TSC2. These genes can cause TS, but having only one of these can result in the disease. Researchers are working to find out exactly what each of these genes do and how they affect TS, but they think the genes suppress tumor growth and are important in the fetal development of the skin and brain.
A parent with a mild case of TS may not even be aware of the condition until their child is diagnosed. Two-thirds of cases of TS are the result of spontaneous mutation, with neither parent passing on the gene. The reason for this mutation is a mystery, and there’s no known way to prevent it.
A diagnosis of TS can be confirmed with genetic tests. When considering genetic testing for family planning, it’s important to remember that only one-third of TS cases are inherited. If you have a family history of TS, it’s possible to get genetic testing to see if you carry the gene.
Symptoms of Tuberous Sclerosis
There’s a broad range of symptoms of TS, which vary greatly from one person to another. Very mild cases can present few, if any, symptoms, and in other cases, people have a variety of intellectual and physical disabilities.
The symptoms of TS can include:
- developmental delays
- intellectual disabilities
- an abnormal heart rhythm
- noncancerous tumors of the brain
- calcium deposits on the brain
- noncancerous tumors of the kidneys or heart
- growths around or underneath the fingernails and toenails
- growths on the retina or pale patches on the eye
- growths on the gums or tongue
- pitted teeth
- areas of the skin that have decreased pigment
- red patches of skin on the face
- raised skin with a texture like an orange peel, which is usually on the back
Diagnosis of Tuberous Sclerosis
TS is diagnosed by genetic testing or a series of tests that includes:
- an MRI of the brain
- a CT scan of the head
- an electrocardiogram
- an echocardiogram
- a kidney ultrasound
- an eye exam
- looking at your skin under an Wood’s lamp, which emits ultraviolet light
Seizures or delayed development are often the first sign of TS. There’s a wide range of symptoms associated with this condition, and a precise diagnosis will require a CT scan and an MRI along with a full clinical exam.
Tumors of Tuberous Sclerosis
Tumors from TS aren’t cancerous, but they may become very dangerous if they’re not treated.
- Brain tumors can block the flow of cerebral spinal fluid.
- Heart tumors can cause problems at birth by blocking blood flow or causing an irregular heartbeat. These tumors are usually large at birth but generally get smaller as your child ages.
- Large tumors can get in the way of normal kidney function and lead to kidney failure.
- If tumors in the eye grow too large, they can block the retina, causing vision loss or blindness.
Treatment of Tuberous Sclerosis
Because symptoms can vary so much, there’s no universal treatment for TS and treatment is planned for each individual. A treatment plan must be tailored to meet your needs as symptoms develop. Your doctor will conduct regular exams and monitor you throughout your life. Monitoring should also include regular kidney ultrasounds to check for tumors.
Here are some treatments for specific symptoms:
Seizures are very common among people with TS. They can impact your quality of life. Medications can sometimes bring seizures under control. If you have too many seizures, brain surgery can be an option.
Mental Disability and Developmental Delay
The following are all used to help those who have mental and developmental problems:
- special educational programs
- behavioral therapy
- occupational therapy
Growths on Skin
Your doctor can use a laser to remove small growths on the skin and improve your skin’s appearance.
Surgery can be done to remove tumors and improve the function of vital organs.
In April 2012, the U.S. Food and Drug Administration granted accelerated approval for use of a drug called everolimus. This drug can be used in adults with TS who have benign tumors of the kidney. As medical care continues to advance, treatment for the symptoms of TS is also improving. Research is ongoing. Currently, there’s no cure.
Long-Term Outlook of Tuberous Sclerosis
If your child shows signs of developmental delay, behavioral problems, or mental impairment, early intervention can significantly improve their ability to function.
Serious complications from TS include uncontrollable seizures and tumors of the brain, kidney, and heart. If these complications aren’t treated, they can lead to premature death.
People diagnosed with TS should find a doctor who understands how to monitor and treat their condition. Because symptoms vary so greatly in each person, so does long-term outlook.
There’s no known cure for TS, but you can expect to have a normal lifespan if you have good medical care.