Prevalence and Mutation Analysis of Medium-Chain Acyl-CoA Dehydrogenase Deficiency Detected by Newborn Screening in Hefei, China

Abstract

Medium-Chain Acyl-CoA Dehydrogenase Deficiency (MCADD) is a metabolic disorder caused by mutations in the ACADM gene, leading to impaired fatty acid oxidation. The present study aims to analyze the prevalence and genetic mutation characteristics of MCADD among newborns in Hefei, China, providing insights for the diagnosis, treatment, and prevention of MCADD. A retrospective analysis was conducted on data from newborns diagnosed with MCADD at the Hefei Newborn Disease Screening Center between January 2016 and December 2024. Screening was performed using tandem mass spectrometry (MS/MS), complemented by next-generation sequencing (NGS) for genetic testing. Out of 880,224 screened newborns, 16 cases of MCADD were diagnosed, resulting in a prevalence of 1 in 55,014. A total of 31 mutation sites in the ACADM gene were identified, with 18 different mutation types. The hotspot mutations were c.449-452del (p.T150Rfs*4) and c.1085G>A (p.G362E), each with a mutation frequency of 16.13% (5 out of 31). Additionally, three novel mutations were identified: c.468+5G>A, c.854C>G, and c.428_431delinsTCTTCTTTTGTT. Following diagnosis, patients received health education, dietary guidance, and symptomatic treatment, all resulting in favorable prognoses without any acute metabolic decompensation events. The prevalence of MCADD is lower in Asia compared to Europe and America. The hotspot mutations for MCADD in Hefei are c.449-452del and c.1085G>A. Diagnosis should integrate results from both octanoylcarnitine (C8) levels and genetic testing. Early screening, diagnosis, treatment, and scientific prevention strategies are essential for reducing adverse outcomes in children with MCADD.