Janeiro, PatríciaJotta, RitaRamos, RubenFlorindo, CristinaVentura, Fátima V.Vilarinho, LauraTavares de Almeida, IsabelGaspar, Ana2020-05-112020-05-112019-03Eur J Pediatr. 2019 Mar;178(3):387-394. doi: 10.1007/s00431-018-03315-2. Epub 2019 Jan 70340-6199http://hdl.handle.net/10400.18/6652Fatty acid β-oxidation (FAO) disorders have a wide variety of symptoms, not usually evident between episodes of acute decompensations. Cardiac involvement is frequent, and severe ventricular arrhythmias are suspected of causing sudden death. Expanded newborn screening (ENS) for these disorders, hopefully, contribute to prevent potentially acute life-threatening events. In order to characterize acute decompensations observed in FAO-deficient cases identified by ENS, a retrospective analysis was performed, covering a period of 9 years. Demographic data, number/type of acute decompensations, treatment, and follow-up were considered. Eighty-three clinical charts, including 66 medium-chain acyl-CoA dehydrogenase deficiency (MCADD), 5 carnitine-uptake deficiency (CUD), 3 carnitine palmitoyltransferase I and II (CPT I/II) deficiency, 5 very long-chain acyl-CoA dehydrogenase deficiency (VLCADD), and 4 multiple acyl-CoA dehydrogenase deficiency (MADD) cases were reviewed. Nineteen patients had acute decompensations (1 CPT I, 1 CPT II, 3 MADD, 14 MCADD). Six patients developed symptoms previously to ENS diagnosis. Severe clinical manifestations included multiple organ failure, liver failure, heart failure, and sudden death. Long-chain FAO disorders had the highest number of decompensations per patient. Conclusion: Despite earlier diagnosis by ENS, sudden deaths were not avoided and acute decompensations with severe clinical manifestations still occur as well.What is Known: Severe ventricular arrhythmias are suspected to cause unexpected death in FAO disorders; Neonatal screening intends to reduce the incidence of severe metabolic crisis and death. What is New: Acute severe decompensations occurred in FAO disorders diagnosed through neonatal screening; Sudden deaths were not avoided by starting treatment precociously.engAcyl-CoA DehydrogenaseAcyl-CoA Dehydrogenase, Long-ChainAmino Acid Metabolism, Inborn ErrorsCardiomyopathiesCarnitineCarnitine O-PalmitoyltransferaseChildChild, PreschoolCongenital Bone Marrow Failure SyndromesEarly DiagnosisFemaleFollow-Up StudiesHumansHyperammonemiaHypoglycemiaInfantInfant, NewbornLipid Metabolism, Inborn ErrorsMaleMetabolism, Inborn ErrorsMitochondrial DiseasesMultiple Acyl Coenzyme A Dehydrogenase DeficiencyMuscular DiseasesNeonatal ScreeningPrognosisRetrospective StudiesSeverity of Illness IndexDoenças Genéticasjournal article10.1007/s00431-018-03315-2