串联质谱检测和高通量测序对青海地区新生儿出生缺陷筛查和诊断的横断面调查

Cross-sectional study on screening and diagnosis of neonatal birth defects in the Qinghai area by tandem mass spectrometry and high throughput sequencing

目的运用串联质谱检测和高通量测序(NGS)技术,初步分析青海高海拔地区新生儿出生缺陷的发病率及病种情况,探讨青海地区行串联质谱检测+NGS对新生儿出生缺陷防治的价值。方法对2018年1月8日至10月18日青海部分地区活产新生儿足跟血行串联质谱遗传代谢病筛查(包含20种氨基酸代谢病、12种脂肪酸代谢病和17种有机酸代谢病),对串联质谱筛查结果异常的新生儿人群及串联质谱筛查人群中具有特殊面容、结构畸形新生儿,母亲有不良孕产史的新生儿行NGS检测,考察串联质谱+NGS筛查(包含2 742个已知致病基因)新生儿出生缺陷的作用和价值。结果研究期间共收集新生儿干血滴滤纸片4 016份(例),男性2 125例(51.6%),汉族2 332例(58.1%),藏族755例(18.8%),回族659例(16.4%),串联质谱筛查提示代谢异常59例(1.47%),提示遗传代谢病(IMD)可能5例,继发改变可能54例。经NGS基因分析确诊3例IMD,包括氨基酸代谢病2例(高苯丙氨酸血症2例)以及脂肪酸代谢病1例(原发性肉碱缺乏症),遗传代谢病总发病率为1/1 339。NGS检测基因变异8例(含3例IMD),拷贝数变异6例。青海地区汉、藏、回民族新生儿血氨基酸及肉碱水平差异有统计学意义(P<0.05)。结论青海高原地区新生儿串联质谱IMD筛查阳性率较国内平原地区高;NGS不仅可以从基因水平确诊质谱筛查提示的阳性病例,还可以诊断高危新生儿串联质谱筛查无法检出的其他新生儿出生缺陷。

Objective To explore the value of tandem mass spectrometry(MS/MS)and targeted next-generation sequencing(NGS)for the prevention and intervention of neonatal birth defects,we examined the incidence and spectrum of genomic disorders in newborns in Qinghai using MS/MS and NGS.Methods Dried blood spots were collected to determine amino acids and acylcarnitines by MS/MS(including 20 kinds of amino acid metabolic diseases,12 kinds of fatty acid metabolic diseases and 17 kinds of organic acid metabolic diseases)conducted in neonates from Qinghai,which were recruited between January 8 and October 12 in 2018.Among them neonates with abnormal tandem mass spectrometry screening results,special facial features and structural abnormalities,and their mothers with bad obstetric history were screened by high throughput sequencing(NGS,including 2,742 known pathogenic genes).The positive samples were verified by sanger sequencing.Results Four thousand and sixteen newborns in Qinghai were enrolled in this project,including 2,125 male cases(51.6%).The total group consisted of 58.1%Han people,18.8%Tibetans and 16.4%Hui people,with 59 MS/MS screening positive(1.47%),including 5 cases indicating IMD and 54 of secondary changes.Three cases of IMD(0.074%)were further diagnosed by NGS analysis.The observed abnormalities comprised 2 of amino acid metabolic diseases(PKU 2 cases)and 1 fatty acid metabolism disease(PCD),with an overall IMD incidence of 1 in 1,339.Eight cases with genetic variation(including 3 cases of IMD)and 6 cases with copy number variation were identified by NGS.Additionally,differences were observed between Han,Tibetan and Hui populations on the concentration levels of amino acids and acylcarnitines.Conclusion The incidence of IMD in newborns in Qinghai is higher than that in other areas reported in China.Our results suggest that NGS can not only confirm the suspicious but uncertain results indicated by MS/MS,but also effectively detect risk and carrier status for a wide range of neonatal birth defects that are not detectable by MS/MS.