What condition is associated with a rotting fish urine odor?

The condition associated with a rotting fish urine odor is trimethylaminuria. This metabolic disorder results from the inability to properly break down trimethylamine, a compound found in certain foods like fish, eggs, and legumes. When trimethylamine is not metabolized properly, it accumulates in the body and is excreted in urine, sweat, and breath, leading to the characteristic fishy odor.

This condition may not manifest until after the introduction of certain dietary triggers, which can exacerbate the symptoms. It is often diagnosed based on clinical presentation and confirmed by urine tests that detect elevated levels of trimethylamine.

The other conditions listed have distinct odors or symptoms that are not similar to trimethylaminuria. Acetoneuria, for instance, leads to a sweet, fruity odor due to the presence of ketone bodies, while maple syrup urine disease causes a smell reminiscent of burnt sugar or maple syrup due to the accumulation of branched-chain amino acids. Phenylketonuria results in a musty or mousy odor because of the buildup of phenylalanine. Each of these metabolic disorders presents with specific biochemical disturbances and clinical features that differentiate them from trimethylaminuria.