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Tuberous Sclerosis Complex

Tuberous Sclerosis Complex (TSC) is a rare genetic condition which affects 1 in 6000 people. According to TSC Ireland, the support group for people with TSC and their families in Ireland, there are an estimated 700 people with TSC in Ireland. It causes tumours or growths in the organs including the brain, eyes, kidney, lungs, skin, teeth and heart. These tumours are usually not cancerous but the effects they can have vary greatly between people with TSC. Some people will have a mild from of the disease with barely noticeable symptoms. For others, the tumours can lead to a wide variety of medical problems. Epilepsy is extremely common in those diagnosed with TSC, so this section of our website will particularly focus on this.  

Causes of TSC

TSC is caused by genetic mutations on the TSC1 or TSC2 gene. These may be unique to the person in three quarters of cases but they may be inherited from an affected parent in a quarter of cases.


Epilepsy is the most common medical problem in TSC affecting 90% of cases. Lesions on the brain such as cortical tubers are small areas of the cortex (surface of the brain) that have not developed normally and these can lead to seizures. When tumours cause epilepsy in a person with TSC the impact also varies between people who can experience a range of seizure types. Where seizures present before  the age of 12 months, one of the syndromes associated is Infantile Spasms (West Syndrome). In this regard early diagnosis and treatment of seizures when they emerge in early life is very important. Other types of seizures common in TSC are focal, myoclonic, atonic, tonic clonic and absences. In people with TSC seizures can become difficult to treat.


TSC may also lead to hydrocephalus, intellectual disability, developmental delay, autism, ADHD, kidney and lung problems and skin abnormalities. In addition to these medical conditions there can be increased behavioural issues and anxiety. There is a wide spectrum of impact, from mild to severe, in terms of how symptoms will present.

Some individuals with TSC have very mild symptoms and few effects whereas others may have much more complex and medically challenging problems which are difficult to manage and treat. In terms of epilepsy the main concern would be the potential risk of status epilepticus from prolonged seizures and this is a medical emergency.


Although TSC is present from birth it may not be obvious from the outset and may only be diagnosed later as symptoms emerge. Due to the variability in type and severity of symptoms some cases of TSC may be detected earlier than others. Seizures are often the first sign of TSC and the tumours can be detected on scans. Young children with TSC may initially have developed Infantile Spasms before being diagnosed with TSC.


There is no cure for TSC but the conditions it causes may be treated with a range of therapies including Anti-Seizure Medication (ASMs), surgery, or educational and behavioural supports.

Further Information