Neoseq for neonatal screening of fatty acid oxidation disorders / 中华围产医学杂志

ABSTRACT

Objective:To explore the value of Neoseq in screening and diagnosis of neonatal fatty acid oxidation disorders (FAOD).Methods:A retrospective case-control study was conducted on 163 500 live births in Changzhou city from April 2015 to April 2021. The following two models were adopted for FAOD screening and diagnosis. (1) Traditional mode Heel blood samples were obtained from all subjects for initial screening using tandem mass spectrum (TMS), followed by next-generation sequencing (NGS) and other differential diagnostic testings for those with positive results. (2) Neoseq Neoseq was performed on the true positive, negative and false positive cases according to the traditional mode screening results. The detection rate, additional discovery, reporting period, and other parameters of the two models for FAOD were described and compared.Results:(1) Detection and diagnosis of FAOD A total of 18 confirmed cases of FAOD were detected through the traditional model, with an incidence of 1/9 083 in Changzhou city. The positive rate was 0.55% (907/163 500) for initial TMS and 0.04% (73/163 500) for the second. The positive predictive value was 2.0%(18/907), with a false positive rate of 98%(889/907) in the initial screening. (2) The results of Neoseq ①Pathogenic mutations were detected in 16 of the 18 confirmed cases, and the coincidence rate of mutation sites between the two methods was 16/18. The other two confirmed cases were missed diagnosed by Neoseq, including one β-ketothiolase deficiency with only one detected pathogenic mutation and one medium-chain acyl-CoA dehydrogenase deficiency without any detected pathogenic mutation. ②No pathogenic mutations were detected in the 57 false-positive cases by Neoseq. ③Among the 100 negative cases in initial screening, DUOX2 heterozygous mutation, and MTTL1 hemizygous mutation were detected in one case each. ④The median period of results reporting was 43.5 d (28-104 d) for the traditional mode and 12 d (10-15 d) for the Neoseq mode. Conclusions:Neoseq has a high detection rate for FAOD. Combined with TMS screening, Neoseq reduces the false-positive rate of biochemical screening, rapidly identifies genetic causes by shortening the results waiting time and covers diseases that couldn't be detected by traditional biochemical methods.