Which metabolic condition can lead to "sweaty feet" odor in the urine?

The presence of a "sweaty feet" odor in the urine is specifically associated with isovaleric acidemia, which is a metabolic disorder characterized by the deficiency of the enzyme isovaleryl-CoA dehydrogenase. This condition leads to the accumulation of isovaleric acid and other metabolites in the body, which can then be excreted in the urine. The metabolic byproducts, particularly isovalerylglycine, contribute to the characteristic odor that resembles sweaty feet.

In isovaleric acidemia, the buildup of these substances can cause neurological symptoms, as the metabolites can be toxic at high levels. The unique "sweaty feet" smell is one of the key hallmarks that may prompt further investigation into metabolic disorders in affected individuals.

The other conditions listed do not typically present with this specific odor in the urine. For example, cystic fibrosis may cause salty skin and respiratory symptoms due to thick mucus, while phenylketonuria primarily leads to a musty odor due to the accumulation of phenylalanine. Smith-Lemli-Opitz syndrome is associated with various dysmorphic features and developmental delays but does not have a notably characteristic urine odor like isovaleric acidemia. This