Abstract Fish malodor syndrome or Fish Odor Syndrome (FOS) is a genetic disorder in which the patient emits a foul odor caused by trimethylamine. People with this syndrome cannot lead a normal social life and some suffer from clinical depression and suicidal thoughts. In this review the clinical biochemical and genetic features of the disorder are described, as well as the psychosocial sequels. The principles of therapy, including dietary, pharmacological and life style changes will also be discussed. Keywords: Fish malodor syndrome, genetic disorder, trimethylamine, therapy Abbreviations: FOS-fish odor syndrome, TMA- Trimethylamine, TMAO - Trimethylamine-oxide, TMAU-trimethylaminuria, FMO3-Flavin monooxygenase 3 Introduction Claire, a young woman, suffered for years of a very unpleasant smell from her breath and body. People would shout at her to brush her teeth. People said she smelled of poo. She knew that they were thinking: ‘she doesn’t wash ', although she washed several times a day. She said it even forced her to quit her job as a care assistant in a residential home. Her life was miserable, she even contemplated suicide. However, after watching a television program about someone with FOS, …show more content…
The substance responsible for the unpleasant smell is trimethylamine (TMA). TMA is normally formed in the intestine by bacterial action on choline or trimethylamine- Oxide. TMA passively diffuses across cell membranes and enters the hepatic circulation where it is oxidizes by Flavin monooxygenase 3 (FMO3) into the odorless Trimethylamine-oxide (TMAO). The disorder is most commonly caused by an inherited deficiency in FMO3, the vital enzyme for the metabolism of trimethylamine [2]. When TMA is not processed properly it can build up in the body. The excess TMA is released in a person 's urine, sweat and breath, and causes the odor characteristic of