Type of disease: Rare conditions
Trimethylaminuria (TMAU) is a metabolic disorder in which an individual is not able to break down trimethylamine into smaller parts. Trimethylamine is the substance that gives fish their distinctive smell. Since an individual with TMAU is unable to break down trimethylamine, they tend to have a fish-like odor coming from their sweat, urine, reproductive fluids, and breath. TMAU is caused by a mutation in the FMO3 gene and is inherited in an autosomal recessive pattern. This condition can be diagnosed by a test to measure the amount of trimethylamine in urine. Genetic testing can also be performed using a blood sample to diagnose TMAU. Although there is no cure for TMAU, the condition can be managed by reducing the amount of trimethylamine in the body. For example, people with TMAU can modify their diet to avoid foods with high levels of trimethylamine.Source: Genetic and Rare Diseases Information Center (GARD), supported by ORDR-NCATS and NHGRI.