The TS 200 Study aims to document and describe the lifetime of someone with Tuberous Sclerosis (TSC), and to identify factors that may lead to intellectual, cognitive, and psychiatric difficulties. Phase one began with the recruitment of 125 children aged 0 to 16 years, living in the United Kingdom (UK) with TSC. In 2013, phase two marked the first follow-up, during which baseline assessments were repeated. Phase three followed in 2015, and most recently, in 2025, phase four involved another round of baseline assessments, due to be released soon. In addition to baseline assessments in phase four, TS-2000 is also conducting online focus groups and testing of a mobile app on new participants living with TSC.