Tehran University of Medical Sciences Case Reports in Clinical Practice 2538-2683 9 1 2024 10 22 3 5 EN Mahtab Ordooei Children Growth Disorder Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran. AND Mother and Newborn Health Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran. Razieh Fallah Children Growth Disorder Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran. AND Department of Pediatrics, Shahid Sadoughi University of Medical Sciences, Yazd, Iran. Maryam Saeida-Ardekani Mother and Newborn Health Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran. Fahimeh Soheilipour Minimally Invasive Surgery Research Center, Iran University of Medical Sciences, Tehran, Iran Mahdieh Yavari Dr. Mazaheri’s Medical Genetics lab, Yazd, Iran. AND Division of Genetics, Department of Cell, Molecular Biology and Microbiology, Faculty of Science and Biotechnology, University of Isfahan, Isfahan, Iran. Mahta Mazaheri Mother and Newborn Health Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran. AND Department of Medical Genetics, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran. 2023 05 21 2024 05 28 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 seizure whose initial screening test was in favor of organic acidemia of the isovaric acidemia (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 considered to be a rare case. https://crcp.tums.ac.ir/index.php/crcp/article/view/829 https://crcp.tums.ac.ir/index.php/crcp/article/download/829/622