Original ArticlesA novel deletion in the flavin-containing monooxygenase gene (FMO3) in a Greek patient with trimethylaminuriaForrest, Susan M.a,b; Knight, Melaniea; Akerman, Beverley R.c; Cashman, John R.d; Treacy, Eileen P.cAuthor Information aMurdoch Children's Research Institute, Royal Children's Hospital, Parkville, Victoria, Australia, bDepartment of Paediatrics, University of Melbourne, Royal Children's Hospital, Parkville, Victoria, Australia, cMontreal Children's Hospital Research Institute and McGill University, Montreal, Quebec, Canada and dHuman BioMolecular Research Institute, San Diego, California, USA Received 19 April 2000; accepted 2 August 2000 Correspondence to Dr Susan Forrest, Murdoch Children's Research Institute, Royal Children's Hospital, Parkville, Victoria, 3052, Australia Tel: +61 3 8341 6267; fax: +61 3 9348 1391; e-mail: [email protected] unimelb.edu.au Pharmacogenetics: March 2001 - Volume 11 - Issue 2 - p 169-174 Buy Abstract Mutations of the flavin-containing monooxygenase type 3 gene (FMO3) that encode the major functional form present in adult human liver, have been shown to cause trimethylaminuria. We now report a novel homozygous deletion of exons 1 and 2 in an Australian of Greek ancestry with TMAuria, the first report of a deletion causative of trimethylaminuria. The deletion occurs 328 bp upstream from exon 1. The 3′-end of the deletion occurs in intron 2, 10013 base pairs downstream from the end of exon 2. The deletion is 12226 bp long. For the proband homozygous for the human FMO3 gene deletion, it is predicted that in addition to loss of monooxygenase function for human FMO3 substrates, such as TMA and other amines, the proband will exhibit decreased tolerance of biogenic amines, both medicinal and those found in foods. © 2001 Lippincott Williams & Wilkins, Inc.