Abstract: Objective:To explore the significance of tandem mass spectrometry in screening for neonatal genetic and metabolic diseases，and to learn about the incidence and distribution of neonatal genetic metabolic diseases in Weifang.Methods:Totally 77 974 neonates from Weifang  were, screened by tandem mass spectrometry from June 2013 to April 2016.Suspected positive samples were clarified by tandem mass spectrometry，urine gas chromatography/mass spectrometry and gene analysis.Results:Among the 77 974 neonates,1 721 were suspected to be positive, and 32 cases were diagnosed with genetic metabolic diseases the incidence being 1/2 437. There were 12 cases of methylmalonic acidemia，10 cases of hyperphenylalaninemia，3 cases of hyperprolinemia，3 cases of  primary carnitine deficiency，1 case of glutaric acidemia I，1 case of 3-methylcrotine glucosinuria，1 case of carnitine palmitoyltransferase Ⅱ deficiency and 1 case of short chain acyl-CoA dehydrogenase deficiency.Conclusion:The incidence is high in Weifang area, which may be the high incidence area of genetic metabolic diseases. Screening for neonatal diseases by tandem mass spectrometry is beneficial to the early detection, diagnosis and treatment of neonatal genetic and metabolic diseases, effectively safeguarding children's health and improving the quality of the population.

Key words: Genetic metabolic diseases, Tandem mass spectrometry, Neonatal screening