"The fish malodour syndrome (also known as the fish odour syndrome and trimethylaminuria) is a metabolic disorder characterized by the presence of abnormal amounts of the dietary-derived tertiary amine, trimethylamine, in the urine, sweat, expired air, and other bodily secretions. Trimethylamine itself has the powerful aroma of rotting fish, and this confers upon the sufferer a highly objectionable body odour, which can be destructive to the personal, social, and work life of the affected individual. In recent years, much progress has been made at all levels - clinical, epidemiological, biochemical, and genetic - in our understanding of this unfortunate condition.

Trimethylaminuria (TMAU), also known colloquially as the fish malodour syndrome, provides an excellent example of how genetically determined variability in the metabolism of a dietary derived chemical, namely trimethylamine, can result in a distressing clinical condition. At a more general level it reflects just how genetic constitution can adversely influence interactions with one's diet. In the past 15 years much has been learned about this particular metabolic disorder, at one time considered to be extremely rare in its occurrence, but in the light of new information, opinions about this are now having to be revised.

Bio-chemically, the disorder is characterized by the excretion of excessive amounts of a simple tertiary aliphatic amine, trimethylamine, in the urine, sweat, and breath as well as other bodily secretions, and this confers upon an individual a very unpleasant body odour resembling that of rotting fish. These “greater-than-normal” amounts of trimethylamine are present due to a failure in removing it via the usual oxidation route to the non-odorous metabolite, trimethylamine N-oxide, owing to a mismatch in the enzymes capacity to undertake this reaction and the substrate load it has to process. At the clinical level, the condition can be extremely distressing for the affected individual and can be responsible for a general destructive effect on the schooling, personal and social lives, as well as having an impact in adult life upon careers".  (Extract from Drug Metabolism Disposition Journal, April 1 2001 vol. 29 no. 4 pages 517-521).

The urine test for Trimethylaminuria is now available through Mullhaven Medical Laboratory.  The cost of the test = £191 and may be ordered on line by pressing the button.      It is recommended that a high choline diet is taken 24 hours prior to the urine sample being taken.  Please also be aware that it can take up to 4 weeks for the results to come back from the referring laboratory.

Back to Laboratory Services