Expanded screening for neonatal inherited metabolic disorders by tandem mass spectrometry in an eastern Chinese population

Abstract

Abstract Objective To analyze the newborn screening results, distribution characteristics and incidence rate for inherited metabolic disorders (IMD) by tandem mass spectrometry (MS/MS) in Huai'an. Methods Blood samples were collected from 97410 newborns born in Huai'an from June 2018 to December 2021. Amino acids, acylcarnitines, and succinylacetone in the blood were detected by non-derivatized MS/MS. Gene detection and gas chromatography-mass spectrometry (GC-MS) were carried out to diagnose positive neonates. Data were analyzed using descriptive statistics. Results From 2018 to 2021, the screening rate of inherited metabolic disorders detected using MS/MS in Huai'an increased from 21.15–99.53%.Twenty-five cases of inherited metabolic disease were diagnosed, and the overall incidence rate was 1/3896. Among them, there were 9 cases of disorders of amino acid metabolism(1/10823), 10 cases of disorders of organic acid metabolism(1/9741), and 6 cases of disorders of fatty acid oxidation(1/16235). The top three diseases with the highest incidence were phenylalanine hydroxylase deficiency(1/12176), methylmalonic acidemia(1/24352), and primary carnitine deficiency (1/24352). Among the 25 children clinically diagnosed with IMD, 84.00% (21 cases) underwent gene diagnosis. Biallelic mutations were identified in 21 children, which were inherited from their parents. Conclusion Our study suggests that newborn screening for IMD by tandem mass spectrometry is necessary, which could improve the quality of patient's life and reduce the burden on family and society. More attention should be paid to the early screening, diagnosis and treatment of neonatal genetic metabolic diseases.