Hereditary leiomyomatosis and renal cell cancer (HLRCC; OMIN #150800) is a rare autosomal-dominant disorder caused by a heterozygous germline mutation in the fumarate hydratase (FH) gene, which encodes an enzyme that is part of the tricarboxylic acid cycle [1]. The gene discussed is FH; the disease is hereditary leiomyomatosis and renal cell cancer.