串联质谱联合气相色谱-质谱检测遗传性代谢病

目的 应用串联质谱检测干血滤纸片中的氨基酸和酰基肉碱谱,联合气相色谱-质谱技术检测尿液中有机酸谱,对遗传性代谢病进行筛查和诊断.方法 留取4981例临床疑似遗传性代谢病儿童的干血滤纸片、尿或尿滤纸片,利用串联质谱仪检测血中氨基酸和酰基肉碱,利用气相色谱-质谱仪检测尿中有机酸,部分患儿结合相关酶活性测定及基因突变分析进行诊断.结果 在4981例患儿中共诊断319例(6.4%)24种遗传代谢病,其中氨基酸代谢病155例(48.6%),8种疾病;有机酸血症150例(47.0%),10种疾病;脂肪酸13氧化代谢病14例(4.4%),6种疾病.结论 串联质谱对氨基酸和脂肪酸代谢病的诊断具有特异性,气相色谱-质谱对有机酸血症的诊断具有特异性,部分氨北基酸代谢病需要这2种技术联合应用才能诊断.

Diagnosis of inborn errors of metabolism using tandem mass spectrometry and gas chromatography mass spectrometry

Objective To investigate the effects of tandem mass spectrometry (MS/MS) combined with gas chromatography mass spectrometry (GC-MS) in the diagnosis of inborn errors of metabolism in children. Methods Amino acids and acylcarnitines in the dry blood filter papers were tested by MS/MS, and the organic acid profiles in urea were tested by GC-MS among 4981 children suspected to be with inborn errors of metabolism from more than 100 hospitals in China. A few pediatric patients underwent analysis of activity of enzyme and gene mutation analysis too. Results 319 of the 4981 children (6.4%) were diagnosed as with 24 kinds of diseases: 155 of the 319 cases (48.6%) with 8 kinds of amino acid diseases (97 with hyperphenylalaninemia, 14 with maple syrup urine disease 13 with ornithine transcarbamylase deficiency, 13 with citrullinemia type Ⅱ, 10 with tyrosinemia type Ⅰ , 5 with citrullinemia type Ⅰ ,2 with homocystinuria, and 1 with arginasemia) ; 150 of the 319 cases (47.0%) were diagnosed as with 10 kinds of organic acidemias (81 with methylmalonic acidemia, 17 with propionic acidemia, 17 with multiple CoA carboxylase deficiency, 11 with glutaric acidemia type Ⅱ, 8 with isovaleric acidemia, 6 with β-keto thiolase deficiency, 5 with 3-methylcrotonyl-CoA carboxylase deficiency, and 3 with 3-hydroxy-3-methylglutaryl-CoA lyase deficiency) ; 14 cases (4.4%) were diagnosed as with 6 kinds of fatty acid disorders (5 with medium chain acyl-CoA dehydrogenase deficiency, 3 with very long chain acyl CoA dehydrogenase deficiency, 2 with short chain acyl-CoA dehydrogenase deficiency, 2 with multiple acyl-CoA dehydrogenase deficiency, 1 with carnitine palmitoyl transferase type Ⅱ , and 1 with carnitine palmitoyl transferase type Ⅰ ). Conclusion MS/MS is specific for amino acid diseases and fatty acid disorders. GC-MS is specific for detect organic acidemias. And the diagnoses of part of amino acid diseases need the combination of both methods.