ABSTRACT
<p><b>OBJECTIVE</b>To study the application of tandem mass spectrometry (MS/MS) in the selective screening of inborn errors of metabolism (IEM) in high risk children and to understand the positive rate and types of IEM.</p><p><b>METHODS</b>MS/MS was used to examine 552 blood samples from high risk cases of IEM who came from 8 hospitals in Shijiazhuang, Hebei Province.</p><p><b>RESULTS</b>Sixty-four children (11.6%) were confirmed with IEM by the MS/MS, including 33 cases of methylmalonic acidemia or propionic acidemias, 2 cases of phenylketonuria, 3 cases of carnitine palmotoyl transferase I deficiency, 1 case of long-chain acyl-CoA dehydrogenase deficiency, 2 cases of medium-chain acyl-CoA dehydrogenase deficiency, 6 cases of maple syrup urine disease, 2 cases of short-chain acyl-CoA dehydrogenase deficiency, 2 cases of glutaric acidemia type I, 2 cases of isovaleric acidemia, 2 cases of homocystinuria, 4 cases of carnitine deficiency, 1 case of tyrosinemia, 1 case of argininosuccinic aciduria, 2 cases of citrullinemia and 1 case of argininemia.</p><p><b>CONCLUSIONS</b>MS/MS can be used to screen and classify IEM.</p>