Objective: To investigate the epidemiological characteristics, phenotype, genotype, and prognosis of medium-chain acyl-CoA dehydrogenase deficiency (MCADD) in the Chinese population.
Methods: A retrospective analysis was performed for the clinical data of the neonates who underwent screening with high-performance liquid chromatography-tandem mass spectrometry from January 2009 to June 2018 and were diagnosed with MCADD by gene detection.
Results: A total of 2 674 835 neonates underwent neonatal screening, among whom 12 were diagnosed with MCADD. Gene detection was performed for 10 neonates with MCADD and found 13 mutation types at 16 mutation sites of the ACADM gene, among which there were 7 reported mutations (p.T150Rfs*4, p.M1V, p.R206C, p.R294T, p.G310R, p.M328V, and p.G362E), 5 novel mutations (p.N194D, p.A324P, p.N366S, c.118+3A>G, and c.387+1del G), and 1 exon 11 deletion; p.T150Rfs*4 was the most common mutation (4/16). The detection rate of mutation sites in the ACADM gene was 80%. No phenotype-genotype correlation was observed. Dietary guidance and symptomatic treatment were given after confirmed diagnosis. No acute metabolic imbalance was observed within 4-82 months of follow-up. All neonates had good prognosis except one who had brain dysplasia.
Conclusions: MCADD is relatively rare in southern China, and p.T150Rfs*4 is a common mutation in the Chinese population. Cases with positive screening results should be evaluated by octanoylcarnitine C8 value and gene detection.
目的: 探讨中链酰基辅酶A脱氢酶缺乏症（MCADD）中国人群流行病学特征、表型、基因型及预后。
方法: 回顾性分析2009年1月至2018年6月期间经高效液相色谱串联质谱（HPLC-MS/MS）筛查并结合基因检测诊断为MCADD的新生儿资料。
结果: 2 674 835例接受筛查的新生儿中诊断MCADD的12例（1/222 902）。其中10例接受基因检测，发现ACADM基因16个突变位点的13种突变类型：7种为已报道突变（p.T150Rfs*4、p.M1V、p.R206C、p.R294T、p.G310R、p.M328V、p.G362E）；5种新突变（p.N194D、p.A324P、p.N366S、c.118+3A > G、c.387+1del G）和1例11号外显子缺失，以p.T150Rfs*4最常见（4/16）。ACADM基因突变位点检出率80%。未见表型-基因型相关性。确诊后给予饮食指导及对症治疗，随访4~82个月期间未见急性代谢失衡发作，除1例合并脑发育不良外均预后良好。
结论: MCADD在中国南方人群相对罕见；p.T150Rfs*4为中国人群热点突变；筛查阳性的病例建议联合辛酰基肉碱检测及基因判断。