海南省少数民族地区新生儿原发性肉碱缺乏症筛查及SLC22A5基因突变特点

Screening of neonatal primary carnitine deficiency and SLC22A5 gene mutation characteristics in ethnic minority areas of Hainan Province

目的分析海南省少数民族地区新生儿原发性肉碱缺乏症(primary carnitine deficiency,PCD)筛查情况及溶质载体家族22A5(solute carrier family 22 member 5,SLC22A5)基因突变特点。方法通过液相(色谱)串联质谱分析技术对2014年6月至2016年6月海南省8个少数民族自治市县52403例新生儿血氨基酸谱、游离肉碱(free carnitine,C0)及酰基肉碱进行检测,召回PCD初筛可疑阳性的新生儿及其母亲复查,分析确诊PCD新生儿及PCD母亲所生新生儿的血酰基肉碱谱动态变化,采用Sanger测序法结合MassArray技术测定确诊病例的SLC22A5基因突变位点,对PCD新生儿补充左卡尼汀治疗,随访,观察患儿发育情况。结果海南省8个少数民族市县2年期间检出PCD新生儿8例,发病率为1/6550;PCD母亲12例,发病率为1/4367;PCD新生儿组初筛时C0、(C3+C16)水平与PCD母亲所生新生儿组相比,差异无统计学意义(P>0.05);PCD新生儿组复筛时C0、(C3+C16)水平均比初筛时降低(P<0.05);PCD母亲所生新生儿组复筛时C0水平比初筛时增高,(C3+C16)水平均比初筛时降低(P<0.05);PCD新生儿检出8种变异,最常见的是c.1400C>G(p.S467C)、c.51C>G(p.F17)、c.760C>T(p.R254X);1种为新发突变,为c.1380C>A(p.N460K)。PCD母亲检出7种变异,最常见的是c.1400C>G(p.S467C)、c.51C>G(p.F17L)、c.1195C>T(p.R399W),1例重型变异c.760C>T(p.R254X);8例PCD均接受左卡尼汀治疗,预后良好,但终止治疗可诱发不良事件。结论海南省8个少数民族市县新生儿PCD发病率较高,液相(色谱)串联质谱分析技术可有效检出PCD,增加多种酰基肉碱量化指标(C3+C16)可提升筛查性能;c.1400C>G(p.S467C)、c.51C>G(p.F17)可能成为海南省少数民族地区新生儿PCD的SLC22A5基因热点突变类型;左卡尼汀治疗效果好,预后良好。

Objective To analyze the screening status of neonatal primary carnitine deficiency(PCD)and the mutation characteristics of solute carrier family 22 A5(SLC22 A5)in the minority areas of Hainan Province.Methods Blood amino acids,free carnitine(c0)and acyl carnitine of 52403 newborns in 8 minority autonomous cities and counties of Hainan Province from June 2014 to June 2016 were detected by liquid chromatography tandem mass spectrometry(lc-ms/MS),the dynamic changes of the blood acyl carnitine spectrum in the neonates and their mothers with suspected positive PCD were analyzed,the mutation site of SLC22 A5 gene was detected by Sanger sequencing and MassArray technique,and the development of PCD neonates was observed.Results In 8 ethnic minority cities and counties of Hainan Province,8 newborns were detected during 2 years of PCD,the incidence rate was 1/6550;12 PCD mothers,the incidence rate was 1/4367;the level of C0,(c3+C16)at the time of initial screening was compared with that of newborns born to PCD mothers,there was no significant difference(P>0.05);the level of C0 and C3+C16 in the group of newborn infants with PCD was lower than that in the group of newborn infants with PCD(P<0.05);the level of C0 and C3+C16 were higher than that in the group of newborn infants with PCD(P<0.05).There were 8 variations in PCD neonates,the most common of which were c.1400 c>G(p.S467 C),c.51 C>G(p.F17),c.760 C>T(p.R254 X).One was a new mutation,c.1380 C>A(p.N460 K).PCD mother detected seven variants,the most common were c.1400 c>g(p.S467 C),c.51 C>G(p.F17 L),c.1195 c>T(P.R399 W),one severe variant c.760 C>T(P.R254 X),all 8 patients were treated with levocarnitine,the prognosis was good,but termination of treatment could induce adverse events.Conclusion The incidence of PCD in newborns is relatively high in 8 ethnic minority cities and counties in Hainan Province.Liquid(chromatographic)tandem mass spectrometry can effectively detect PCD,and the addition of multiple acylcarnitine quantitative indicators(C3+C16)can improve screening performance;c.1400 C>G(p.S467 C),c.51 C>G(p.F17)may become the hot-spot mutation types of SLC22A5 gene in neonatal PCD in ethnic minority areas of Hainan Province;L-carnitine treatment has a good effect and a good prognosis.