Coloured historical image of the face of a young man with skin lesions (cutaneous angiofibromas) caused by tuberous sclerosis. Tuberous sclerosis is a rare genetic disorder that causes benign (non-cancerous) tumours to grow in the brain and other organs, including the kidneys, heart, eyes, lungs and skin. It can cause seizures, intellectual disabilities and delayed development, as well as lung and kidney diseases.