FH and hereditary leiomyomatosis and renal cell cancer: In contrast to these somatic mutations, germline mutations associated with UL were observed in the gene encoding the Krebs cycle enzyme fumarate hydratase (FH) in hereditary leiomyomatosis and renal cell carcinoma (HLRCC; OMIM 150800), a rare and dominantly-transmitted Mendelian syndrome (Alam et al. 2001, Launonen et al. 2001, Tomlinson et al. 2002) as well as in rare cases of nonsyndromic UL (Barker et al. 2002, Kiuru et al. 2002).