A case report of a mild form of multiple acyl-CoA dehydrogenase deficiency due to compound heterozygous mutations in the ETFA gene

BACKGROUND: Multiple acyl-CoA dehydrogenase deficiency (MADD), previously called glutaric aciduria type II, is a rare congenital metabolic disorder of fatty acids and amino acids oxidation, with recessive autosomal transmission. The prevalence in the general population is estimated to be 9/1,000,000 and the prevalence at birth approximately 1/200,000. The clinical features of this disease are divided into three groups of symptoms linked to a defect in electron transfer flavoprotein (ETF) metabolism. In this case report, we present new pathogenic variations in one of the two ETF protein subunits, called electron transfer flavoprotein alpha (ETFA), in a childhood-stage patient with no antecedent. CASE PRESENTATION: A five-year-old child was admitted to the paediatric emergency unit for seizures without fever. He was unconscious due to hypoglycaemia confirmed by laboratory analyses. At birth, he was a eutrophic full-term new-born with a normal APGAR index (score for appearance, pulse, grimace, activity, and respiration). He had one older brother and no parental consanguinity was reported. A slight speech acquisition delay was observed a few months before his admission, but he had no schooling problems. MADD was suspected based on urinary organic acids and plasma acylcarnitine analyses and later confirmed by genetic analysis, which showed previously unreported ETFA gene variations, both heterozygous (c.354C > A (p.Asn118Lys) and c.652G > A (p.Val218Met) variations). Treatment was based on avoiding fasting and a slow carbohydrate-rich evening meal associated with L-carnitine supplementation (approximately 100 mg/kg/day) for several weeks. This treatment was maintained and associated with riboflavin supplementation (approximately 150 mg/day). During follow up, the patient exhibited normal development and normal scholastic performance, with no decompensation. CONCLUSION: This case report describes new pathogenic variations of the ETFA gene. These compound heterozygous mutations induce the production of altered proteins, leading to a mild form of MADD.