The clinical features of TSC considered of major significance are: facial angiofibromas or forehead plaque, nontraumatic periungual fibromas, three or more hypomelanotic macules, shagreen patch, multiple retinal nodular hamartomas, cortical tuber, subependymal nodule, subependymal giant cell astrocytoma, cardiac rhabdomyoma, lymphangioleiomyomatosis, and renal angiomyolipoma.