串联质谱技术在遗传性代谢病高危儿童筛查中的初步应用

目的　开展遗传性代谢病高危儿童筛查检测。方法　临床疑诊遗传性代谢病儿童 10 4例 ,男 77例 ,女 2 7例 ,年龄 (4 8± 4 2 )岁。手指采血 ,滴于专用采血滤纸上。干血滤纸片与含已知量的氨基酸、酰基肉碱同位素内标一起 ,经甲醇萃取 ,盐酸正丁醇衍生后 ,用串联质谱仪分析血片中氨基酸谱和酰基肉碱谱及其浓度。结果　在 10 4例标本中 ,检出阳性标本 10例 (9 6 % ) ,其中酪氨酸血症1例 ,同型胱氨酸血症 1例 ,高鸟氨酸血症 1例 ,甲基丙二酸血症 2例 ,丙酸血症 1例 ,3 羟基 3 甲基戊二酸裂解酶缺乏症 1例 ,中链酰基辅酶A脱氢酶缺乏症 2例 ,酰基肉碱转移酶Ⅱ缺乏症 1例。结论串联质谱技术可检测 30余种遗传性代谢病 ,包括氨基酸代谢紊乱、有机酸代谢紊乱和脂肪酸代谢紊乱性疾病 ,高危遗传性代谢病患儿的筛查有重要价值

A pilot study of selective screening for high risk children with inborn error of metabolism using tandem mass spectrometry in China

OBJECTIVE: The new technology of tandem mass spectrometry is exerting a significant impact on the diagnostics of inborn metabolic errors, and allows to detect a number of these disorders in a single step. The aim of the present study was to establish a dry blood filter paper method for amino acid and acylcarnitine profiles test using tandem mass spectrometry and to apply the method for selective screening in high risk children with inborn error of metabolism. METHOD: The study group consisted of 104 high risk cases of inborn error of metabolism from 5 pediatric hospitals in Shanghai and Beijing were tested from November 2002 to June 2003; 77 were males and 27 females, the means age was 4.8 +/- 4.2 years. These patients had mental retardation, slow development, psychological abnormalities, muscle hypotonia, jaundice, hepatosplenomegaly, recurrent vomiting, and convulsion. Laboratory examinations suggested metabolic acidosis, hypoglycemia, hyperammonemia and hyperlactacidemia. Phenylketonuria was excluded in this study by routine phenylalanine screening. The control group consisted of 308 children, 170 males and 138 females. The blood was collected on filter paper, punched and extracted into methanol solution with stable isotope labeled internal standards, then derivatized with butanolic-HCl. After preparation, the samples were analyzed by tandem mass spectrometry (API 2000). RESULTS: Ten of 104 patients (9.6%) were positive in our selective screening program, including one with tyrosinemia, one with homocystinuria, one with hyperornithinemia, two with methylmalonic acidemia, one with propionic acidemia, one with 3-hydroxy-3-methylglutaryl-CoA lyase deficiency, two with medium chain acyl-CoA dehydrogenase deficiency, and one with carnitine palmitoyl transferase type II deficiency. CONCLUSION: The authors established a fast, accurate and sensitive tandem mass spectrometry method for amino acid and acylcarnitine profiles analysis, nearly 30 metabolic diseases including amino acid disorders, organic acid disorders and fatty acid oxidation disorders could be detected, most of the diseases that cause death and disability represent preventable entities by early diagnosis and treatment. The results indicated the importance of selective screening for high risk patients with inborn error of metabolism.