Abstract: Objective  To determine the prevalence of primary carnitine deficiency(PCD) in neonates in Shijiazhuang area, and to further analyze the genetic mutations.
Methods  Tandem mass spectrometry was used to detect the blood free carnitine and acylcarnitine in neonates,and carnitine transporter gene mutation was detected in suspected children.
Results  A total 160 061 neonates, 17 were diagnosed, including 9 children with PCD(prevalence rate was 1/17 785), and 8 children with maternal carnitine deficiency. 〖JP2〗Nine children with PCD had a primary screening value of blood free carnitine of 4.47(1.77-6.78) μmol/L, and a recall of 4.83(2.80-7.32) μmol/L,〖JP〗 accompanied by a decrease in the levels of various acylcarnitines. Among 9 children with PCD, 4 cases were tested for SLC22A5 gene, 〖JP2〗including 1 compound heterozygous, 1 homozygous and 2 heterozygous. Gene mutation analysis revealed 4 mutation sites: c.865C>T, c.1400C>G, c.428C>〖JP〗T and c.1462C>T.
Conclusion  Application of tandem mass spectrometry in neonatal disease screening can detect PCD early. The prevalence of PCD in Shijiazhuang area is 1/17 785; 4 mutation sites of SLC22A5 gene are found.

Key words: primary carnitine deficiency, tandem mass spectrometry, neonates