关键词: 中链酰基辅酶A脱氢酶缺乏症, 串联质谱, 基因突变

Abstract: Objective To investigate the prevalence,clinical and gene mutation characteristics of medium chain acyl-CoA dehydrogenase deficiency(MCADD) in neonates in Qingdao area. Methods The acylcarnitine levels in the blood of 278 180 neonates from newborns screening program in Qingdao area were measured by tandem mass spectrometry.from January 2015 to August 2018.The suspected MCADD neonates were diagnosed by retrospective analysis of the urine organic acids and medium chain acyl-CoA dehydrogenase(ACADM) gene mutation. Results Four cases were diagnosed with MCADD,with the prevalence rate of 0.001 4%(1/69 545).There was no obvious abnormality in clinical manifestations,and the levles of medium chain acyl carnitine(C6-C10) increased in the four patients.Seven different mutations in the ACADM gene were identified in four cases.And one case was homozygous mutation:c.1 040G>T(p.G347V)/ c.1 040G>T(p.G347V).The other three cases were detected with compound heterozygous mutations,including c.157C>T(p.R53C)/ c.709-1G>A,c.1085G>A(p.G362E)/ c.461T>G(p.L154W)and c.587G>A(p.G196E)/ c.387+1delG.One case had increasing levels of 4-hydroxyphenylacetic acid and 4-hydroxyphenylpyruvate and hepatic insufficiency.Dietary guidance was given to the MCADD patients.No clinical symptoms were manifested and physical and intellectual development were normal during the follow-up period. Conclusion Inherited metabolic disease screening by tandem mass spectrometry for neonatal screening combined with gene detection can help early diagnosis of MCADD,which is of great significance to prevent the arrest of disease and improve the quality of life in MCADD children.

Key words: medium chain acyl-CoA dehydrogenase deficiency, tandem mass spectrometry, gene mutation