Isovaleric acidemia associated with an intellectual disability: case report

*Correspondence: [e-mail].

Abstract

Case Presentation: The subject of the study was a 15-years-old girl in the ninth grade of elementary school. She was diagnosed with isovaleric acidemia in the neonatal period through screening tests performed. Despite her being treated with L-carnitine, Biotin, L-Glycine and Metabolic Formula for her pathology, since entering school, the patient had performed poorly, especially in language and calculation subjects. Furthermore, she had difficulty making friends with people the same age as her and was socially isolated. The patient was then diagnosed with mild intellectual disability.

Discussion: Isovaleric acidemia (IVA) is a hereditary metabolic disorder in which there is a inadequacy of isovaleryl-CoA dehydrogenase, an enzyme that catalyzes the third step in leucine catabolism. This metabolic alteration leads to an accumulation of isovaleric acid, isovaleryl-carnitine, 3-hidroxyisovaleric acid and isovalerylglycine. There are two forms of IVA, an acute and a chronic form. It may present as an acute episode of metabolic acidosis causing a drop in consciousness, coma, and death. The chronic form is associated with episodes of metabolic decompensation in catabolic states, manifesting itself through delayed neuropsychomotor development, which may not be present until the child is a year old. Although IVA is, largely, a metabolic disease, it can be presented with other clinical features. Some studies have shown that it can be associated with neurological deficits, such as motor syndromes and cognitive disabilities.

Final Comments: Isovaleric acidemia has a wide range of clinical forms of presentation, and there are forms that are asymptomatic or with mild cognitive changes. In our patient, it started a standard course, but later on the disorder evolved with a mild intellectual disability. The purpose of this report is to show an uncommon finding in an organic aciduria.

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Artikel online veröffentlicht:
12. Mai 2025