Tuberous sclerosis complex (TSC) is a rare autosomal dominant disorder that afflicts 1:6000–1:10,000 live births and is caused by pathologic loss-of-function (LoF) variants in either TSC complex subunit 1 (TSC1) or TSC complex subunit 2 (TSC2).1,2 TSC is characterized by pleomorphic benign tumors of multiple organ systems, including the kidney, brain, skin, heart, and lung. The gene discussed is TSC1; the disease is benign neoplasm.