Mental Health Neurodevelopmental Disorders Autism Causes & Risk Factors Tuberous Sclerosis Raises the Risk of Autism By Lisa Jo Rudy Lisa Jo Rudy Facebook LinkedIn Twitter Lisa Jo Rudy, MDiv, is a writer, advocate, author, and consultant specializing in the field of autism. Learn about our editorial process Updated on October 25, 2020 Medically reviewed Verywell Health articles are reviewed by board-certified physicians and healthcare professionals. These medical reviewers confirm the content is thorough and accurate, reflecting the latest evidence-based research. Content is reviewed before publication and upon substantial updates. Learn more. by Brian Levine, MD Medically reviewed by Brian Levine, MD LinkedIn Brian Levine, MD, MS, FACOG, is board-certified in obstetrics and gynecology, as well as in reproductive endocrinology and infertility. Learn about our Medical Expert Board Print Tuberous sclerosis (TSC) is a rare medical disorder. It's rarely mentioned relative to autism, but in fact, most people with TSC can actually be diagnosed with an autism spectrum disorder. According to the NIH: UpperCut Images / Getty Images "Tuberous sclerosis (TSC) is a rare genetic disease that causes benign tumors to grow in the brain and on other vital organs such as the kidneys, heart, eyes, lungs, and skin. It commonly affects the central nervous system. In addition to the benign tumors that frequently occur in TSC, other common symptoms include seizures, mental retardation, behavior problems, and skin abnormalities." Connection Between TSC and Autism About 50% of all people diagnosed with TSC are also diagnosable with autism. As many as 14% of people with autism spectrum disorders AND seizure disorder may also be diagnosable with TSC. Researchers aren't completely sure why autism and TSC seem to be connected, but according to the TC Alliance, the recent finding suggests that in TC: "...there are abnormalities in the way different parts of the brain connect to each other, not only in the temporal lobes but in many other parts of the brain as well. These abnormal connections, which occur independent of tubers, are associated with ASD in children and adults with TSC. Additionally, many studies have shown that seizures and, particularly, early onset of seizures, are associated with delayed development and ASD. Therefore, it is likely a combination of factors that leads to the much higher chance of ASD." Even with this new information, however, it is not clear whether the seizures cause autism or whether the seizures are actually indications of abnormalities which also cause autism. Recognizing and Diagnosing TSC It is possible to inherit TSC from a parent. Most cases, though, are due to spontaneous genetic mutations. That is, a child's genes mutate even though neither parent has either TSC or a faulty gene. When TSC is inherited, it usually comes from only one parent. If a parent has TSC, each child has a 50% chance of developing the disorder. Children who inherit TSC may not have the same symptoms as their parent and they may have either a milder or a more severe form of the disorder. In most cases, the first clue to recognizing TSC is the presence of seizures or delayed development. In other cases, the first sign may be white patches on the skin. To diagnose TSC, doctors use CT or MRI scans of the brain, as well as an ultrasound of the heart, liver, and kidneys. Once a child has been diagnosed with TSC, it is important to be aware of the strong possibility that he or she will also develop autism. While the symptoms of both disorders do overlap, they are not identical — and early treatment for autism can lead to the most positive results. Was this page helpful? Thanks for your feedback! Sign up for our Health Tip of the Day newsletter, and receive daily tips that will help you live your healthiest life. Sign Up You're in! Thank you, {{form.email}}, for signing up. There was an error. Please try again. What are your concerns? Other Inaccurate Hard to Understand Submit 0 Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. "Tuberous Sclerosis Fact Sheet," NINDS. NIH Publication No. 07-1846 Hunt A, Shepherd C. A Prevalence Study of Autism in Tuberous Sclerosis. J Autism Dev Disord. 1993 Jun;23(2):323-39. Smalley SL. Autism and Tuberous Sclerosis. J Autism Dev Disord. 1998 Oct;28(5):407-14.