[Trimethylaminuria: fish-odor syndrome].

Fish-odor syndrome is due to a rare metabolic defect in which there is massive excretion of the volatile tertiary amine, trimethylamine (TMA) in the urine. The typical fish-like odor of TMA also appears on the breath or in the sweat of affected individuals. In normal man TMA is oxidized to its odorless N-oxide derivative. TMA is of dietary origin, formed by intestinal bacterial degradation of the choline in egg yolk, liver, soybeans, etc., or by reduction of TMA-oxide present in high concentrations in marine fish. 2 sisters with the tentative diagnosis of trimethylaminuria are presented.