- Mutations of the flavin-containing monooxygenase gene (FMO3) cause trimethylaminuria, a defect in detoxication. Treacy, E.P., Akerman, B.R., Chow, L.M., Youil, R., Bibeau, C., Lin, J., Bruce, A.G., Knight, M., Danks, D.M., Cashman, J.R., Forrest, S.M. Hum. Mol. Genet. (1998)