Tuberous sclerosis is a polymorphic, dominantly inherited syndrome caused by an 
inactivating mutation in a tumor suppressor gene. The disease involves benign 
tumors in several distinct organs such as the skin, kidneys, heart and central 
nervous system. The tumors interfere with organ function, but only some exhibit 
a significant tendency to grow. The clinical picture of tuberous sclerosis 
varies from nearly symptomless to a severe disease. Treatment of growing tumors 
associated with tuberous sclerosis is changing significantly, since their growth 
can be suppressed with rapamycin and its derivatives.