[Trimethylaminuria: three different mutations in a single family].

Background: primary trimethylaminuria or fish odor syndrome is a genetic metabolopathy characterized by the accumulation of trimethylamine, a very volatile compound in body secretions. Case report: we present the case of a healthy 8-month-old patient who, after the introduction of fish in the diet, starts a bad body odor that does not disappear with bathing. The mother visits the pediatrician repeatedly but no disorder is identified.