Tuberous sclerosis

Tuberous sclerosis complex (TSC) is a rare, multi-system genetic disorder that causes the growth of benign tumors in various organs, including the brain, kidneys, heart, liver, eyes, lungs, and skin. Symptoms may include seizures, intellectual disability, and developmental delay. TSC has autosomal dominant inheritance, meaning a child with TSC either has one affected parent (about 1/3 of cases) or a spontaneous (de novo) mutation (about 2/3 of cases). It is caused by a mutation of either of two genes, TSC1 and TSC2, which code for the proteins hamartin and tuberin, respectively. TSC2 mutations are more frequent and have usually more severe symptoms. These proteins act as tumor growth suppressors, regulating cell proliferation and differentiation. Without them, tumors are more likely to appear. Life for individuals with TSC varies depending on the severity of the symptoms, but most patients have normal life expectancy through routine medical care. The prevalence of the disease is estimated to be 7 to 12 in 100,000. The disease is often abbreviated to tuberous sclerosis, which refers to the hard swellings in the brains of patients, first described by French neurologist Désiré-Magloire Bourneville in 1880.