[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 beta-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).


CONCLUSIONS
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.
Han
Lian-Shu
LS
Department of Pediatric Endocrinology and Genetic Metabolism, Shanghai Institute for Pediatric Research, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200092, China.
Ye
Jun
J
Qiu
Wen-Juan
WJ
Gao
Xiao-Lan
XL
Wang
Yu
Y
Jin
Jing
J
Gu
Xue-Fan
XF
D000293:Adolescent; D000596:Amino Acids / Q000097:blood; D002648:Child; D002675:Child, Preschool; D004252:DNA Mutational Analysis; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008659:Metabolic Diseases / Q000097:blood / Q000175:diagnosis* / Q000235:genetics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D053719:Tandem Mass Spectrometry / Q000379:methods*
D000596:Amino Acids