- Biallelic inactivation of fumarate hydratase (FH) occurs in nonsyndromic uterine leiomyomas but is rare in other tumors. Lehtonen, R., Kiuru, M., Vanharanta, S., Sjöberg, J., Aaltonen, L.M., Aittomäki, K., Arola, J., Butzow, R., Eng, C., Husgafvel-Pursiainen, K., Isola, J., Järvinen, H., Koivisto, P., Mecklin, J.P., Peltomäki, P., Salovaara, R., Wasenius, V.M., Karhu, A., Launonen, V., Nupponen, N.N., Aaltonen, L.A. Am. J. Pathol. (2004)