A Case Report of Isovaleric Acidemia without Acidosis

The deficiency of isovaleryl-CoA dehydrogenase leads to an inborn recessive error of leucine metabolism named isovaleric acidemia (IVA). Its presentation may be either in the neonatal period as an acute episode of metabolic acidosis or later as a “chronic intermittent form.” Normal development is promoted by early diagnosis and treatment with a protein-restricted diet and supplementation with carnitine and glycine. The present case was a 35-day-old boy admitted with seizures, whose initial screening test was in favor of organic acidemia of the isovaleric acidemia type (Ammonia: 200 μmol/L). As the venous blood gas (VBG) analysis revealed no acidosis, newborn metabolic screening was repeated. Typical laboratory findings and elevated levels of C5 and C5/C2 confirmed isovaleric acidemia again. As the above patient had no acidosis while the other tests, including laboratory and genetic analysis, were in favor of IVA, he was considered to be a rare case.