The TSC1 gene is one of the two major genes associated with tuberous sclerosis complex (TSC), a multisystem genetic disorder characterized by benign tumors called hamartomas that can affect the brain, skin, kidneys, heart, lungs, and eyes, and which may lead to seizures, developmental differences, autism spectrum features, renal angiomyolipomas (benign fatty tumors), and pulmonary lymphangioleiomyomatosis (a condition that impacts lung function). Management of TSC requires multidisciplinary lifelong surveillance, including periodic brain and abdominal imaging, dermatologic and ophthalmologic evaluations, renal monitoring, and early treatment of seizures or organ involvement, with mTOR inhibitor therapies available for certain tumor types. TSC1-related TSC is not known to be more common in the Ashkenazi Jewish population.
Pathogenic variants in TSC1 exhibit autosomal dominant inheritance. This means there is a 50% chance the condition can be passed from generation-to-generation. First degree relatives (parents, siblings, children) have a 50% chance to have the same pathogenic variant whereas second degree relatives (grandparents, aunts/uncles, nieces/nephews, half-siblings) have a 25% chance. More distant relatives have lower chances of having the same pathogenic variant when one is identified in the family.
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Written December 2025
