尿素酶预处理-气相色谱-质谱技术筛查遗传性代谢病高危儿  

Screening of Inherited Metabolic Disorders in High-Risk Infants Using Urease Pretreatment-Gas Chromatography-Mass Spectrometry

作　　者：高平明[1] 郝虎[1,2] 李思涛[1] 刘冰清[1] 刘梦娴[1] 李雯丽[2] 肖昕[1,2] 

机构地区：[1]中山大学附属第六医院儿科,广州510655 [2]中山大学附属第六医院遗传代谢病实验室,广州510655

出　　处：《实用儿科临床杂志》2012年第20期1569-1571,1606,共4页Journal of Applied Clinical Pediatrics

基　　金：中山大学"百人计划"人才基金项目(20071153);中山大学青年基金项目(20110739)

摘　　要：目的通过尿素酶预处理-气相色谱-质谱法(UP-GC-MS)检测1 330例高危儿遗传性代谢病(IMD)及代谢紊乱的发病率,为临床诊断和治疗提供依据。方法留取出生1 d～3岁高危儿尿液样本,尿液标本经尿素酶去尿素、加内标、除蛋白、真空干燥处理、残余物用双(三甲基硅烷基)三氟乙酰胺/三甲基氯硅烷衍生后进样,应用气相色谱-质谱联用仪分析其尿液中有机酸、氨基酸、糖类、多醇、嘌呤和嘧啶等成分。结果 1 330例高危儿中,共890例(66.9%)存在代谢异常。其中确诊IMD 21例(1.6%),包括甲基丙二酸尿症8例,高苯丙氨酸血症3例,尿素循环障碍、半乳糖血症、枫糖尿症、异戊酸血症和丙酸血症各2例;疑似IMD 49例(3.7%),包括酪氨酸血症23例、脂肪酸代谢障碍12例、尿素循环异常8例和Citrin缺陷症6例,其中4例经过串联质谱检测和基因分析得到确诊;确诊非遗传因素所致代谢病40例(3.0%),包括乳酸血症28例及甘油尿症12例;此外,还有780例(58.6%)高危儿存在代谢紊乱,表现为尿半乳糖、4羟基苯乳酸、N-乙酰酪氨酸、乳酸、乳糖、琥珀酸、酮性双羧酸水平增高以及丝氨酸/苏氨酸比例异常。结论 UP-GC-MS是诊断小儿IMD和代谢紊乱的有效方法,必要时应联合应用串联质谱检测及基因分析进行诊断。Objective To detect the incidence of inherited metabolic disorders（IMD） and disorders of metabolism in high - risk infants, and to provide basis for clinical diagnosis by using urease pretreatment - gas chromatography - mass spectrometry （ UP - GC - MS）. Methods Urine samples from high - risk infants of IMD were collected,and they were decomposed with urease,and heptadecanoic acid was added as an internal standard, protein was denaturated with ethanol and precipitate was removed by centrifugation, evaporation was performed to dryness, the residue was trimethylsilylly derivatized with bis （trimethylsilyl） trifluoroacetamide/trimethyl - chlorosilane. GC - MS was used to analyze compositions such as organic acids, amino acids, carbohydrates, pyridoxines, purines and pyrimidines. Results Eight hundred and ninety cases of metabolic disorders were found in 1 330 high - risk infants （ 66.9% ）, including 21 diagnosed cases （ 1.6% ） of inherited metabolic disorders （which included 8 cases of methylmalonic aciduria,3 cases of hyperphenylalaninemia,2 cases of abnormal urea cycle, galactosemia, maple syrup urine disease,isovaleric acidemia and propionic academia, respectively）. There were 49 suspected cases （3.7%） of IMD,inclu- ding tyrosinemia（23 cases） ,abnormal urea cycle（8 cases） ,fatty acid metabolic disorders（ 12 cases） and Citrin defects（6 cases）. In particu- lar,4 cases of the above were diagnosed accurately by tandem mass spectrometry （MS - MS） and genetic analysis. There were 40 cases （3.0%） of non-inherited metabolic disorders （28 cases of lactic acidosis and 12 cases of glycerol aciduria）. There were also 780 cases of metabolic disorders （58.6%） , such as increasing urine levels of galactose ,4 -hydroxy phenyl lactic acid, N- aeetyl tyrosine,lactic acid,lac-tose,succinie acid,ketodicarboxylic, and abnormal serine/threonine ratio. Conclusions UP - GC - MS is an effective method to diagnose IMD and disorders of metabolism in pediatrics. If necessary, MS -

关 键 词：遗传性代谢病 气相色谱-质谱法 高危儿 

分 类 号：R725.8[医药卫生—儿科]