FH and hereditary leiomyomatosis and renal cell cancer: The most striking UL predisposing condition thus far characterized is hereditary leiomyomatosis and renal cell cancer (HLRCC) syndrome, caused by high-penetrance germline mutations in the Fumarate hydratase (FH) gene (Multiple Leiomyoma Consortium et al., 2002; Launonen et al., 2001).