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.
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Objective To investigate the influences of maternal gestational diabetes mellitus (GDM) on amino acid levels in neonates.Methods From June 2016 to May 2017,393 pregnancies diagnosed with GDM in Changzhou Maternity and Child Health Care Hospital Affiliated to Nanjing Medical University and 3 924 normal pregnancies were enrolled in this study.Clinical data of the gravidas and their newborns were collected.Heel blood samples were collected at 72 to 96 hours after birth.Tandem mass spectrometry was performed to detect the levels of 11 amino acids including alanine,arginine,citrulline,glycine,leucine/ isoleucine/hydroxyproline,methionine,ornithine,phenylalanine,proline,tyrosine and valine in neonatal heel blood.Differences in amino acid levels between the two groups were compared by t test.Influences of GDM on neonatal amino acid levels were analyzed by multivariate linear regression.Results Compared with the healthy pregnancy group,neonates in the GDM group had higher levels of methionine [(21.01 ±6.30) vs (19.93±6.47) μmol/L,t=3.159,P=0.002] and phenylalanine [(47.19±9.19) vs (45.78±8.58) μ mol/L,t=3.076,P=0.002],but lower levels of alanine [(280.51 ±64.54) vs (290.15±68.40) μ mol/L,t=2.678,P=0.007],proline [(147.64±30.64) vs (152.36±33.57) μ mol/L,t=2.680,P=0.007],tyrosine [(85.21 ±29.50) vs (90.60± 33.32) μ mol/L,t=3.089,P=0.002] and ornithine [(101.22±28.79) vs (105.83±30.10) μmol/L,t=2.906,P=0.004].Multivariate linear regression analysis showed that GDM was responsible for the increase of methionine (β=0.69,95％CI:0.02 to 1.37,P=0.044) and phenylalanine (β=1.60,95％CI:0.69 to 2.51,P=0.001),and the decrease of tyrosine (β=-4.98,95％CI:-8.42 to-1.54,P=0.005) and ornithine (β=-3.16,95％CI:-6.30 to-0.02,P=0.048) in neonates.Conclusions GDM neonates has increased of methionine and phenylalanine levels and decreased tyrosine and omithine levels.
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Objective To investigate the feasibility of congenital cytomegalovirus (CMV)infection screening by saliva polymerase chain reaction.Methods From November 1,2010 to February 29,2012,6733 newborns born in Changzhou Maternal and Child Health Care Hospital were enrolled.Saliva samples (0.2 ml) were collected within 3 days after birth,CMV-DNA was detected by real time-polymerase chain reaction and hearing screening was done with EroScan transient-evoked otoacoustic emissions at the same time.The positive rate of congenital CMV infection screening was calculated and clinical manifestations were analyzed.Chi square test was applied to statistical analysis.Results Totally 6733 newborns were screened and 107 of them were found to be positive with CMV DNA,the positive rate was 1.59％ (107/6733),among which 88 were asymptomatic (82.2％) and 19 were symptomatic (17.8 ％).The major clinical manifestations of the neonates with positive CMVDNA were pathological jaundice (13 cases),hepatomegaly (5 cases),granulocytopenia,thrombocytopenic purpura,anemia and small for gestational age (two cases each).Fourteen newborns had only one major clinical manifestation,three newborns had two major clinical manifestations and two newborns had three major clinical manifestations.There was no statistical difference between newborns with positive and negative CMV DNA on hearing screening [hearing loss in one ear:8.4％ (9/107) vs 5.8％ (382/6626); hearing loss in two ears:3.7 ％ (4/107) vs 2.4 ％ (159/6626),x2 =2.776,P=0.241].Conclusion It is feasible to screen congenital CMV infection with saliva sample.