Selective screening for inborn errors of metabolism on clinical patients using tandem mass spectrometry in China: A four‐year report

Abstract

We have initiated clinical selective screening for inborn errors of metabolism in China by analysing amino acids and acylcarnitines in a dried blood filter-paper samples using tandem mass spectrometry. Samples from a total of 3070 children suspected of inborn errors of metabolism were collected through a study network which covered most provinces of China. The diagnoses were further confirmed through clinical symptoms, by gas chromatography-mass spectrometry and other biochemistry studies, and in a few cases by DNA analysis. In all, 212 cases were diagnosed (6.6%) including 92 (43.4%) with amino acids disorders (48 with phenylketonuria, 12 with ornithine carbamoyltransferase deficiency, 7 with tyrosinaemia type I, 9 with maple syrup urine disease, 5 with citrullinaemia type I, 8 with citrullinaemia type II, 2 with homocystinuria, and 1 with argininaemia); 107 (50.5%) with organic acid disorders (including 58 with methylmalonic acidaemia, 13 with propionic acidaemia, 6 with isovaleric acidaemia, 7 with glutaric acidaemia type I, 6 with 3-methylcrotonyl-CoA carboxylase deficiency, 2 with 3-hydroxy-3-methylglutaryl-CoA lyase deficiency, 10 with multiple carboxylase deficiency, and 5 with beta-ketothiolase deficiency); and 13 (6.1%) with fatty acid oxidation disorders (including 1 with carnitine palmitoyltransferase deficiency type I, 1 with carnitine palmitoyltransferase deficiency type II, 1 with short-chain acyl-CoA dehydrogenase deficiency, 5 with medium-chain acyl-CoA dehydrogenase deficiency, 3 with very long-chain acyl-CoA dehydrogenase deficiency, and 2 with multiple acyl-CoA dehydrogenase deficiency). It is suggested that tandem mass spectrometry is useful for selective screening of clinically suspected patients. The majority of diseases (94%) in this study were amino acid disorders and organic acid disorders. Fatty acid oxidation disorders are relatively rare in the Chinese, but medium-chain acyl-CoA dehydrogenase deficiency should be further investigated.

Fatty Acid Oxidation Disorders in a Chinese Population in Taiwan

“…Han et al have screened for FAO disorders by MS/MS NBS analysis for patients suspected to have inborn errors and found only a few cases (Han et al 2007). …”

Organic Acidurias: An Updated Review

“…Hans et al [45] studied 3070 children suspected with IMD in China and diagnosed 212 cases with IMD including 92 amino acidurias and 107 organic acidurias.…”

Selective Screening for Inborn Errors of Metabolism: A Report of Six Years Experience

“…In other parts of the world where there is no or a limited NBS program implemented, the laboratories performing Tandem MS analysis for clinically suspected patients, provide information regarding the frequency of these disorders (1,(9)(10)(11)(12)(13)(14). The analysis of dried blood spot (DBS) samples by Tandem MS is increasingly used by many laboratories for selective screening of metabolic diseases considering the high frequency of IEMs mostly due to high consanguinity rate in Turkey.…”