Tuberous sclerosis is a genetic condition that causes features in multiple systems. The characteristic feature is the development of hamartomas. These are benign neoplastic growths of the tissue that they origin from. Hamartomas cause problems based on the location of the lesion. They commonly affect the:
Tuberous sclerosis is caused by mutations in one of two genes:
- TSC1 gene on chromosome 9, which codes for hamartin
- TSC2 gene on chromosome 16, which codes for tuberin
Hamartin and tuberin interact with each other to control the size and growth of cells. Abnormalities in one of these proteins leads to abnormal cell size and growth.
- Ash leaf spots are depigmented areas of skin shaped like an ash leaf
- Shagreen patches are thickened, dimpled, pigmented patches of skin
- Angiofibromas are small skin coloured or pigmented papules that occur over the nose and cheeks
- Subungual fibromata are fibromas growing from the nail bed. They are usually circular painless lumps that grow slowly and displace the nail
- Cafe-au-lait spots are light brown “coffee and milk” coloured flat pigmented lesions on the skin
- Poliosis is an isolated patch of white hair on the head, eyebrows, eyelashes or beard
- Learning disability and developmental delay
- Rhabdomyomas in the heart
- Gliomas (tumours of the brain and spinal cord)
- Polycystic kidneys
- Lymphangioleiomyomatosis (abnormal growth in smooth muscle cells, often affecting the lungs)
- Retinal hamartomas
The classical presentation is a child presenting with epilepsy found to have skin features of tuberous sclerosis. It can also present in adulthood.
Management is supportive with monitoring and treating complications such as epilepsy. There is no treatment for the underlying gene defect.
Last updated April 2019