串联质谱技术在有机酸血症筛查中的应用研究

目的探讨串联质谱技术在遗传性代谢病高危儿童有机酸血症筛查和诊断中的意义。方法遗传性代谢病高危儿童1000例,男642例,女358例,年龄中位数为2岁(5天～15岁),手指采血,滴于滤纸片上。取直径3mm的干血滤纸片放入96孔聚丙烯板,经含酰基肉碱内标的甲醇萃取,盐酸正丁醇衍生后,进行串联质谱分析。结果1000例高危儿童中筛查并诊断有机酸血症40例(4．0％),其中甲基丙二酸血症20例,丙酸血症6例,异戊酸血症3例,戊二酸血症Ⅰ型3例,戊二酸血症Ⅱ型3例,β-甲基巴豆酰辅酶A羧化酶缺乏症1例,β-羟基．3．甲基戊二酰辅酶A裂解酶缺乏症1例,生物素酶缺乏症2例,β-酮硫解酶缺乏症1例。患儿临床表现主要为运动和智力发育落后、抽搐、意识障碍、肌张力低下、呕吐和喂养困难等。常规实验室检查主要表现为酸中毒、高血氨、高乳酸血症和低血糖等。结论串联质谱技术能够通过检测血滤纸片中的不同酰基肉碱浓度,对部分有机酸血症进行快速筛查和诊断,结合尿气相色谱／质谱技术,有助于提高有机酸血症诊断的准确性。     

串联质谱技术在有机酸血症鉴别诊断中的应用

目的探讨串联质谱技术在有机酸血症诊断和鉴别诊断中的作用。方法对2566例遗传性代谢病高危儿童的干血滤纸片进行串联质谱分析,结合尿气相色谱质谱有机酸分析、酶活性测定和基因突变分析,诊断有机酸血症。比较不同有机酸血症间的串联质谱结果差异。结果共确诊有机酸血症82例(3.2%),其中甲基丙二酸血症(MMA)44例,丙酸血症(PA)10例,生物素酶缺乏症4例和全羧化酶合成酶缺乏症2例;患儿丙酰肉碱(propinoylcar-nitine,C3)水平均高于健康儿童上限值(4.0μmol/L)。PA和MMA患儿C3与游离肉碱(C0)比值(C3/C0)、C3与乙酰肉碱(C2)比值(C3/C2)也高于健康儿童上限值;PA患儿同时伴有甘氨酸增高,甲基丙二酸血症患儿甘氨酸正常;生物素酶缺乏症和全羧化酶合成酶症患儿伴3"羟基"异戊酰肉碱(3"hydyoxyl"isovalerylcarnitine,C5"OH)水平增高;3"甲基巴豆酰辅酶A羧化酶缺乏症(5例)、3"羟基"3"甲基戊二酰辅酶A裂解酶缺乏症(3例)和β"酮硫解酶缺乏症(4例)患儿C5"OH水平也增高,前两种疾病仅表现为C5"OH增高,后一种疾病同时伴有异戊烯酰基肉碱水平增高;异戊酸血症5例,仅表现为异戊酰肉碱(C5)增高;戊二酸血症(GA)"Ⅰ型(3例)仅表现为戊二酰肉碱(C5DC)增高,GA"Ⅱ型(2例)除C5DC增高外,伴有多种酰基肉碱增高,两者可作鉴别。结论通过串联质谱酰基肉碱、酰基肉碱比值和氨基酸分析,可对部分有机酸血症进行诊断和鉴别诊断;部分有机酸血症需结合尿气相色谱质谱有机酸分析进行诊断。     

尿滤纸片法气相色谱-质谱分析技术在遗传性代谢病高危筛查诊断中的应用

目的 建立一种适合我国国情的有机酸尿症及其他遗传性代谢病的高危筛查诊断方法。方法 应用滤纸片收集尿标本,建立尿有机酸及氨基酸代谢产物的萃取、衍化和气相色谱-质谱分析方法;成立遗传代谢性疾病高危筛查诊断协作网络并开展工作。结果 352例样本中共检出阳性病例34例(9．66％),病种包括甲基丙二酸血症6例,α—酮戊二酸尿症5例,酪氨酸血症I型4例,二羧酸尿症4例,多种羧化酶缺乏症3例,苯丙酮尿症3例,高乳酸血症3例,丙酸血症2例,鸟氨酸氨甲酰基转移酶缺乏症1例,乙基丙二酸-己二酸尿症1例,戊二酸尿症Ⅱ型1例和3—甲基巴豆酰羧化酶缺乏症1例。常见的临床症状和体征包括智能发育落后、惊厥、肌张力异常和黄疸。常规实验室检查多见代谢性酸中毒、低血糖和高血氨等异常。结论 尿有机酸气相色谱—质谱分析为遗传性代谢病高危筛查诊断的重要技术。应用滤纸片收集尿标本后在遗传代谢病诊断中心进行检测为实用而有效的方法。建立协作网络是成功开展遗传性代谢病高危筛查诊断工作的关键。     

遗传性代谢病致儿童脑发育落后的治疗与预后

目的探讨遗传性代谢疾病致儿童脑发育落后中治疗及影响预后的相关因素。方法用串联质谱仪对278例原因不明的脑发育落后患儿进行血氨基酸谱和酰基肉碱谱筛查,对疑似代谢性疾病患儿进行尿气相色谱/质谱（GC/MS）及相关酶活性检测,对检出的遗传性代谢病患儿的临床资料进行综合分析。结果17/278例（6.15%）确诊为遗传性代谢病,其中甲基丙二酸血症4例,甲基丙二酸血症伴同型胱氨酸尿症4例,丙酸血症3例,鸟氨酸氨甲酰转移酶缺乏症、枫糖尿病、Ⅰ型戊二酸血症、异染色性白质脑病、苯丙酮尿症、生物素酶缺乏症各1例。临床表现为智能及运动发育落后或倒退、惊厥、昏迷、呕吐、肌张力降低、营养不良、嗜睡、反复感染等。实验室检查显示代谢性酸中毒、血氨及血乳酸增高、贫血等。MRI表现为脑萎缩、双侧脑白质T2w高信号或伴T1w低信号、多发性脑软化或囊样变等。起病早、伴严重酸中毒及昏迷的维生素B12无效型甲基丙二酸血症预后极差。患儿经特殊奶方、低蛋白饮食、肉碱、维生素B12及生物素等治疗后,好转11例,死亡5例,未愈1例。结论对原因不明的脑发育落后患儿应予遗传代谢性病筛查;早期、合理治疗有助于改善预后。     

气相-色谱质谱法尿有机酸检测诊断遗传代谢病患儿的疾病谱

目的了解气相色谱-质谱技术检测尿有机酸水平诊断的遗传代谢病患儿的氨基酸、有机酸、脂肪酸氧化代谢病疾病谱。方法回顾性分析2005年1月至2021年12月上海交通大学医学院附属新华医院诊断为遗传代谢病的2 461例患儿的疾病谱, 患儿均通过气相色谱-质谱尿有机酸谱检测, 并结合血串联质谱氨基酸及酰基肉碱检测结果及基因变异检测结果诊断。结果 2 461例患儿中男1 446例, 女1 051例, 共有32种遗传代谢病, 其中氨基酸代谢病10种662例(26.9%), 常见的前6种疾病为高苯丙氨酸血症、希特林蛋白缺乏症、鸟氨酸氨甲酰转移酶缺乏症、枫糖尿病、尿黑酸尿症及酪氨酸血症-Ⅰ型;有机酸血症17种1 683例(68.4%), 常见的前6种疾病为甲基丙二酸血症、丙酸血症、戊二酸血症-Ⅰ型、异戊酸血症、3-甲基巴豆酰辅酶A羧化酶缺乏症及多种羧化酶缺乏症;脂肪酸β氧化代谢病5种116例(4.7%), 常见的前2种疾病为多种酰基辅酶A脱氢酶缺乏症和短链酰基辅酶A脱氢酶缺乏症。结论气相色谱-质谱技术尿有机酸谱检测诊断的疾病中有机酸血症最常见, 然后为氨基酸代谢病及脂肪酸氧化代谢病。     

经高危筛查发现的遗传性代谢病15例分析

目的：提高临床医生对非特异性临床表现的遗传性代谢病的认识,并通过实验室检查早期诊断、早期治疗,减少后遗症。方法：对2003年6月1日至2006年9月30日期间入住上海交通大学医学院附属新华医院儿内科病房的132例非特异性临床表现的高危儿,在常规进行临床生化检查的同时行血串联质谱和尿气相质谱检测。结果：132例中诊断遗传性代谢病15例（11.5%）。其中甲基丙二酸血症(MMA)6例(40％);丙酸血症2例（13.3%）;瓜氨酸血症-II型2例（13.3%）;生物素酶缺乏症1例（6.7%）;酪氨酸血症1例（6.7%）;枫糖尿病1例（6.7%）;鸟氨酸氨甲酰转移酶缺乏症1例（6.7%）;极长链酰基肉碱辅酶A脱氢酶缺乏症1例（6.7%）。结论：对非特异性临床表现疑似遗传性代谢病的高危儿应及时进行串联质谱及气相质谱检查有助于遗传性代谢病的检出。     

串联质谱技术选择性筛查遗传代谢病高危患儿552例初步分析

目的：应用串联质谱（tandem mass spectrometry, MS/MS）技术进行遗传代谢病（IEM）高危儿筛查,初步了解我国 IEM 的发病种类和阳性率,为其有效防治提供科学依据。方法：利用MS/MS技术对在河北省石家庄市8所省、市级医院就医的552例可疑 IEM 患儿的血液样本进行 IEM 筛查。结果：发现阳性患儿64例,阳性率为11.6%。其中甲基丙二酸血症或丙酸血症33例,苯丙酮尿症2例,肉碱棕榈酰转移酶缺乏Ⅰ型3例,长链酰基辅酶 A 脱氢酶缺乏症1例,中链酰基辅酶A脱氢酶缺乏症2例,枫糖尿症6例,短链酰基辅酶A脱氢酶缺乏症2例,戊二酸血症Ⅰ型2例,异戊酸血症2例,同型胱氨酸尿症2例,肉碱缺乏症4例,酪氨酸血症1例,精氨酸琥珀酸尿症1例,瓜氨酸血症2例,精氨酸血症1例。结论：MS/MS技术是筛查诊断IEM的有效工具。     

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

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。     

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

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。     

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目的探讨液质联用串联质谱技术在筛查以黄疸为主要表现的肝病患儿中的临床意义。方法选取2010年4月至2011年4月首都医科大学附属北京儿童医院肝病门诊就诊和消化内科住院且临床表现为黄疸、肝大、肝酶增高的儿童75例。收集其干血滤纸片进行液质联用串联质谱检测,并且进行数据分析。结果 75例患儿中有49例患儿的串联质谱分析结果正常;26例患儿出现不同程度的氨基酸谱或酰基肉碱谱的异常,其中包括有确诊遗传代谢性疾病5例和非遗传代谢性疾病15例,6例患儿尚未明确诊断。结论临床上患儿出现不明原因的肝大、黄疸或肝酶增高等,尤其伴有血氨(NH3)或血清乳酸(LAC)升高时,应该考虑遗传代谢性疾病的可能。一些非遗传代谢性疾病患儿也可因肝脏继发损伤出现氨基酸谱或酰基肉碱谱的异常。     

Welche Rolle bleibt dem selektiven Screening auf Stoffwechselstörungen angesichts des Neugeborenenscreening mit Tandemmassenspektrometrie?

For several decades general neonatal screening for inborn metabolic and endocrine disorders through the examination of dried blood spots has been available in Germany and Austria. More recently, this newborn screening has been extended in these two countries to include tandem mass spectrometry analyses. The extended neonatal screening and its potential have rightly attracted major attention, but the heavy emphasis placed on its potential has also made some pediatricians uncertain about the further need for organic acid/amino acid analyses and other assays performed as selective screening tests for inborn errors of metabolism. We therefore give an introduction to routine and selective newborn screening and present signs, symptoms and laboratory data that can prompt selective metabolic screening.     

串联质谱技术对新生儿遗传代谢病的筛查及随访研究

目的 初步了解串联质谱筛查新生儿遗传代谢病的发生率及确诊病例的随访情况.方法 采用串联质谱方法,对129 415例新生儿进行26种氨基酸、有机酸及脂肪酸代谢性疾病筛查,对确诊病例进行流行病学特点、预后及随访情况进行分析.结果 确诊新生儿遗传代谢病23例,包括氨基酸代谢异常13例、有机酸代谢异常6例及脂肪酸代谢异常4例,发病率为1∶5626.筛查的阳性预测值为2.10％,特异性为99.72％,敏感性为100％.所有确诊病例进行随访,仅有6例出现运动、智力发育落后及代谢紊乱.结论 串联质谱方法能够早期筛查、诊断遗传代谢病,及早干预预后较好;串联质谱筛查方法具有较高的特异性及敏感性,但阳性预测值低,需要进一步提高筛查效率.     

上海地区遗传代谢病的新生儿筛查(英文)

Objectives Inborn errors of metabolism (IEM) has a diverse spectrum and different incidence in different countries, the early diagnosis at presymptomatic stage is imperative to benefic patient from sequelae. Phenylke-tonuria (PKU) / hyperphenylalaninemia (HPA) is the most common metabolism disorder in Shanghai as well as in other regions. The study is to further clarify the incidence of inborn errors of metabolism among newborn in Shanghai. Methods The dried blood spot specimens were collected from near 90 ...     

Glutaric acidemia, type I, missed by newborn screening in an infant with dystonia following promethazine administration

We report a child initially diagnosed with promethazine-induced dystonia despite a lack of response to diphenhydramine therapy. On further evaluation, the child was diagnosed with glutaric acidemia, type I (GA-I), an autosomal recessive inborn error of metabolism caused by the deficiency of glutaryl-CoA dehydrogenase. The characteristic clinical feature of GA-I is an acute encephalopathic and neurologic crisis typically occurring during a catabolic state. Despite slow improvement, many patients do not fully recover from a neurologic crisis, and residual neurologic morbidity can be significant. Although newborn screening using tandem mass spectrometry is expected to enable presymptomatic diagnosis of GA-I, this patient was not detected by newborn screening with tandem mass spectrometry. Therefore, a high suspicion of GA-I must be maintained in the evaluation of childhood dystonia, even when newborn screening results are reportedly normal.     

串联质谱技术在脑发育落后病因诊断中的意义

目的探讨串联质谱技术（MS／MS）在脑发育落后病因诊断及疗效判断中的意义。方法应用串联质谱仪,对158例脑发育落后患儿进行血氨基酸谱和酰基肉碱谱定量检测,对检出的11例代谢性疾病患儿MS／MS结果、尿气相色谱／质谱检测（GC／MS）结果、临床表现及治疗后变化进行综合分析。结果158例中,11例（7．0％）患儿确诊为遗传代谢性疾病,其中甲基丙二酸血症5例,丙酸血症2例,鸟氨酸氨甲酰转移酶缺乏症1例,枫糖尿病1例,苯丙酮尿症1例,生物素酶缺乏症1例。临床表现为智能及运动发育落后或倒退（11例）、惊厥（5例）、昏迷（4例）、呕吐（4例）、营养不良（4例）、嗜睡（3例）、反复感染（3例）、肌张力降低（2例）等。实验室检查显示代谢性酸中毒、血氨及血乳酸增高、贫血等。MRI表现为脑萎缩、双侧脑白质T2w高信号或伴T1w低信号、多发性脑软化或囊样变等。起病早、伴严重酸中毒及昏迷的甲基丙二酸血症预后较差。患儿经维生素B12左旋肉碱、特殊奶方、低蛋白饮食及生物素等治疗后,好转8例,死亡3例。结论串联质谱技术有助于脑发育落后的病因诊断及疗效判断。早期诊断及合理治疗可避免脑组织进一步损害,并改善预后。     

Urinary excretion of l-carnitine and acylcarnitines by patients with disorders of organic acid metabolism: evidence for secondary insufficiency of l-carnitine

Concentrations of l-carnitine and acylcarnitines have been determined in urine from patients with disorders of organic acid metabolism associated with an intramitochondrial accumulation of acyl-CoA intermediates. These included propionic acidemia, methylmalonic aciduria, isovaleric acidemia, multicarboxylase deficiency, 3-hydroxy-3-methylglutaric aciduria, methylacetoacetyl-CoA thiolase deficiency, and various dicarboxylic acidurias including glutaric aciduria, medium-chain acyl-CoA dehydrogenase deficiency, and multiple acyl-CoA dehydrogenase deficiency. In all cases, concentrations of acylcarnitines were greatly increased above normal with free carnitine concentrations ranging from undetectable to supranormal values. The ratios of acylcarnitine/carnitine were elevated above the normal value of 2.0 +/- 1.1. l-Carnitine was given to three of these patients; in each case, concentrations of plasma and urine carnitines increased accompanied by a marked increase in concentrations of short-chain acylcarnitines. These acylcarnitines have been examined using fast atom bombardment mass spectrometry in some of these diseases and have been shown to be propionylcarnitine in methylmalonic aciduria and propionic acidemia, isovalerylcarnitine in isovaleric acidemia, and hexanoylcarnitine and octanoylcarnitine in medium-chain acyl-CoA dehydrogenase deficiency. The excretion of these acylcarnitines is compatible with the known accumulation of the corresponding acyl-CoA esters in these diseases. In this group of disorders, the increased acylcarnitine/carnitine ratio in urine and plasma indicates an imbalance of mitochondrial mass action homeostasis and, hence, of acyl-CoA/CoA ratios. Despite naturally occurring attempts to increase endogeneous l-carnitine biosynthesis, there is insufficient carnitine available to restore the mass action ratio as demonstrated by the further increase in acylcarnitine excretion when patients were given oral l-carnitine.(ABSTRACT TRUNCATED AT 250 WORDS)     

Metabolic screening in children: newborn screening for metabolic diseases past,present and future

Newborn screening began with the diagnosis of phenylketonuria using a simple test applicable to all newborn babies. Treatment could be given before the onset of brain damage with near normal outcomes. Methods became available to screen for and treat a variety of inborn errors of metabolism, but their application was patchy. Screening for hypothyroidism is now universal in the UK, and screening for cystic fibrosis and, more recently, haemoglobinopathies is being implemented nationally. Tandem mass spectrometry allows detection of more than 30 metabolic disorders using the neonatal screening blood spot. Considerable worldwide experience is now available and limited studies have shown favourable outcomes. Following a pilot study, the UK is to adopt tandem mass spectrometry screening for medium-chain acyl-CoA dehydrogenase deficiency. There is the potential to develop expanded newborn screening for aminoacidopathies, urea cycle disorders, organic acidaemias and fatty acid oxidation defects.