Analysis of clinical features, biochemical indices and genetic variants among children with Short/branched-chain acyl-CoA dehydrogenase deficiency detected by neonatal screening / 中华医学遗传学杂志

OBJECTIVE@#To investigate the clinical manifestations, biochemical abnormalities and pathogenic variants among children with Short/branched-chain acyl-CoA dehydrogenase (SBCAD) deficiency detected by neonatal screening.@*METHODS@#A total of 2 730 852 newborns were screened from January 2016 to December 2021 with liquid chromatography tandem mass spectrometry. Suspected SBCAD deficiency patients were diagnosed by urine organic acid analysis and high-throughput gene sequencing analysis. The clinical, biochemical and genetic changes of the confirmed cases were analyzed, in addition with guidance for diet and life management, L-carnitine supplement, and survey of growth and intellectual development.@*RESULTS@#Twelve cases of SBCAD deficiency were diagnosed, which yielded a prevalence of 1/227 571. The lsovaleryl carnitine (C5) of primary screening blood samples was between 0.6 and 2.1 µmol/L, all exceeded the normal range. C5/acety1 carnitine (C2) was between 0.02 and 0.12, with 6 cases exceeding the normal range. C5/propionyl carnitine (C3) was between 0.1 and 1.16, with 5 cases exceeding the normal range. Free carnitine (C0) was between 18.89 and 58.12 µmol, with 1 case exceeding the normal range. Three neonates with abnormal screening results were recommended to have appropriate restriction for protein intake and two were given L-carnitine. During follow-up, their C5 has ranged from 0.22 to 2.32 µmol/L, C5/C2 has ranged from 0.01 to 0.31, C5/C3 has ranged from 0.14 to 1.7. C5 or C5/C2 and C5/C3 were transiently normal in all patients except for case 8 during the neonatal screening and follow-up. C0 was 17.42 ∼ 76.83 µmol/L Urine organic acid analysis was carried out in 9 of the 12 cases, and 2-methylbutyroglycine was elevated in 8 cases. Urine organic acid analysis was carried out in 9 cases, and 2-methylbutyrylglycine was increased in 8 cases. Genetic analysis was carried out for 11 children, and in total 6 ACADSB gene variants were identified, which included 4 missense variants (c.655G>A, c.923G>A, c.461G>A, c.1165A>G), 1 frameshift variant (c.746del) and 1 nonsense variant (c.275C>G). Among these, the C.461G>A variant was unreported previously. The most common variants were c.1165A>G (40.9%) and C.275C>G (22.7%). The patients were followed up for 18 days to 55 months. Only one patient had mental retardation, with the remainders having normal physical and mental development.@*CONCLUSION@#SBCAD deficiency is a rare disease. The detection rate of newborn screening in this study was 1/227 571. Early intervention can be attained in most asymptomatic patients through neonatal screening. In this study, the common gene variants are c.1165A>G and c.275C>G.

A prospective study of genetic screening of 2 060 neonates by high-throughput sequencing / 中华医学遗传学杂志

OBJECTIVE@#To assess the value of genetic screening by high-throughput sequencing (HTS) for the early diagnosis of neonatal diseases.@*METHODS@#A total of 2 060 neonates born at Ningbo Women and Children's Hospital from March to September 2021 were selected as the study subjects. All neonates had undergone conventional tandem mass spectrometry metabolite analysis and fluorescent immunoassay analysis. HTS was carried out to detect the definite pathogenic variant sites with high-frequency of 135 disease-related genes. Candidate variants were verified by Sanger sequencing or multiplex ligation-dependent probe amplification (MLPA).@*RESULTS@#Among the 2 060 newborns, 31 were diagnosed with genetic diseases, 557 were found to be carriers, and 1 472 were negative. Among the 31 neonates, 5 had G6PD, 19 had hereditary non-syndromic deafness due to variants of GJB2, GJB3 and MT-RNR1 genes, 2 had PAH gene variants, 1 had GAA gene variants, 1 had SMN1 gene variants, 2 had MTTL1 gene variants, and 1 had GH1 gene variants. Clinically, 1 child had Spinal muscular atrophy (SMA), 1 had Glycogen storage disease II, 2 had congenital deafness, and 5 had G6PD deficiency. One mother was diagnosed with SMA. No patient was detected by conventional tandem mass spectrometry. Conventional fluorescence immunoassay had revealed 5 cases of G6PD deficiency (all positive by genetic screening) and 2 cases of hypothyroidism (identified as carriers). The most common variants identified in this region have involved DUOX2 (3.93%), ATP7B (2.48%), SLC26A4 (2.38%), GJB2 (2.33%), PAH (2.09%) and SLC22A5 genes (2.09%).@*CONCLUSION@#Neonatal genetic screening has a wide range of detection and high detection rate, which can significantly improve the efficacy of newborn screening when combined with conventional screening and facilitate secondary prevention for the affected children, diagnosis of family members and genetic counseling for the carriers.

Application of MassARRAY genotyping assay in the diagnosis of neonatal genetic metabolic diseases / 中华检验医学杂志

Objective:To investigate the accuracy, effectiveness and feasibility of MassARRAY genotyping assay in the diagnoses of neonatal genetic metabolic diseases.Methods:This is a retrospective study. From December 2016 to January 2020, newborns were screened by tandem mass spectrometry at the Zhejiang Newborn Screening Center, among which the data of 7 922 suspected positive cases of genetic metabolic diseases were collected. These patients were then tested for the common variants of 27 genetic metabolic diseases by MassARRAY genotyping assay, along with further testing using Sanger or next-generation sequencing used to verify and/or further search for potential variants.Results:A total of 1 408 cases were tested with MassARRAY. Among these, 307 cases were confirmed with certain genetic metabolic diseases. The detection rate of hyperphenylalaninemia was the highest, followed by primary carnitine deficiency, short acyl-coA dehydrogenase deficiency and methylmalonic acidemia. With these cases, the consistency of Sanger sequencing and MassARRAY was 100% (307/307). Another 287 cases were identified as carriers by MassARRAY with a 49.1% (141/287) consistency in reference to Sanger sequencing, mainly involving SLC22A5 and MCCC1 genes. Meanwhile, 50.8% (146/287) of these cases were found to have another variant mainly involving PAH, PTS and ACADS genes. The remaining 814 cases have no variants; 158 cases out of these patients have continuously abnormal amino acids, acyl carnitines, urine organic acid and/or other biochemical indices, and were tested by next-generation sequencing, among which 38% (60/158) were detected with two variants. In this study, a total of 513 patients with genetic metabolic disease were diagnosed, and the detection rate of MassARRAY was 59.8% (307/513). Conclusions:MassARRAY genotyping assay can be used as an early molecular screening method for neonatal genetic metabolic diseases. The detection rate is particularly high in diseases with a high concentration of hotspot variants, such as hyperphenylalaninemia and primary carnitine deficiency. The future application value of MassARRAY should be further improved by continuously optimizing its ability to identify new disease genes and potential variable sites.

Long-term follow-up of children with carbamoyl phosphate synthase 1 deficiency detected in newborn screening / 浙江大学学报·医学版

OBJECTIVES@#To investigate genotype-phenotype characteristics and long-term prognosis of neonatal carbamoyl phosphate synthetase 1 (CPS1) deficiency among children through newborn screening in Zhejiang province.@*METHODS@#The clinical and follow-up data of children with CPS1 deficiency detected through neonatal screening and confirmed by tandem mass spectrometry and genetic testing in Zhejiang Province Newborn Disease Screening Center from September 2013 to August 2023 were retrospectively analyzed.@*RESULTS@#A total of 4 056 755 newborns were screened and 6 cases of CPS1 deficiency were diagnosed through phenotypic and genetic testing. Ten different variations of CPS1 genewere identified in genetic testing, including 2 known pathogenic variations (c.2359C>T and c.1549+1G>T) and 8 unreported variations (c.3405-1G>T, c.2372C>T, c.1436C>T, c.2228T>C, c.2441G>A, c.3031G>A, c.3075T>C and c.390-403del). All patients had decreased citrulline levels (2.72-6.21 μmol/L), and varying degrees of elevated blood ammonia. The patients received restricted natural protein intake (special formula), arginine and supportive therapy after diagnosis, and were followed-up for a period ranging from 9 months to 10 years. Three patients experienced hyperammonemia, and one patient each had attention deficit hyperactivity disorder, transient facial twitching and increased muscle tone. One patient died, while the other five surviving patients had normal scores of the Ages & Stages Questionnaires (ASQ) and Griffiths Development Scales up to the present time; 4 cases had combined height or weight lag and one case was normal in height and weight.@*CONCLUSIONS@#Low citrulline levels and hyperammonemia are common in CPS1 deficiency patients in Zhejiang. Most gene variants identified were specific to individual families, and no hotspot mutations were found. Early diagnosis through newborn screening and following standardized treatment can significantly improve the prognosis of the patients.

Results of neonatal screening for congenital hypothyroidism and hyperphenylalaninemia in Zhejiang province from 1999 to 2022 / 浙江大学学报·医学版

OBJECTIVES@#To analyze the results of neonatal screening for congenital hypothyroidism (CH) and hyperphenylalaninemia (HPA) in Zhejiang province from 1999 to 2022.@*METHODS@#A total of 11 922 318 newborns were screened from September 1999 and December 2022 in Zhejiang province. The blood thyroid stimulating hormone (TSH) levels were measured by a fluorescence method and blood phenylalanine (Phe) levels were measured by fluorescence method or tandem mass spectrometry. TSH≥9 μIU/mL was considered positive for CH, while Phe>120 μmol/L and/or Phe/Tyr ratio>2.0 were considered positive for HPA. The positive newborns in screening were recalled, and the gene variations were detected by high-throughput sequencing and MassARRAY tests.@*RESULTS@#The overall neonatal screening rate during 1999-2022 was 89.41% (11 922 318/13 333 929) and the screening rate was increased from 6.46% in 1999 to 100.0% in 2022. A total of 8924 cases of CH were diagnosed among screened newborns with an incidence rate of 1/1336. A total of 563 cases of HPA were diagnosed, including 508 cases of classic phenylketonuria (cPKU) and 55 cases of tetrahydrobiopterin deficiency (BH4D), with an incidence rate of 1/21 176. Ninety-seven out of 8924 cases of CH underwent genetic analysis. Gene mutations were detected in 9 CH related genes, the highest frequency mutations were found in DUOX2 gene (69.0%) with c.3329G>A (p.R1110Q) (18.2%) and c.1588A>T (p.K530X) (17.3%) as the hotspot mutations. There were 81 PAH gene variants detected in a total of 250 cases of cPKU, and c728G>A (p.R243Q) (24.4%), c.721C>T (p.R241C) (15.0%) were the hotspot mutations. Meanwhile 7 novel variants in PAH gene were detected: c.107C>A (p.S36*), c.137G>T (p.G46V), c.148A>G(p.K50E), c.285C>T (p.I95I), c.843-10delTTCC, exon4-7del and c.1066-2A>G. There were 12 PTS gene variants detected in 36 cases of BH4D, and c.259C>T (p.P87S) (31.9%) was the hotspot mutation.@*CONCLUSIONS@#The incident of CH has increased from 1999 to 2022 in Zhejiang province, and it is higher than that of national and global levels; while the incidence of HPA is similar to the national average. DUOX2 gene variation is the most common in CH patients; c.728G>A (p.R243Q) is the hotspot mutation in cPKU patients, while c.259C>T (p.P87S) is the hotspot mutation in BH4D patients.

Analysis of genotypes and biochemical phenotypes of neonates with abnormal metabolism of butyrylcarnitine / 浙江大学学报·医学版

OBJECTIVES@#To investigate the genotypes and biochemical phenotypes of neonates with abnormal metabolism of butyrylcarnitine (C4).@*METHODS@#One hundred and twenty neonates with increased C4 levels detected by tandem mass spectrometry in the neonatal screening at Children's Hospital, Zhejiang University School of Medicine from January 2018 to June 2023 were included. The initial screening data and recalled data of C4 and C4/C3 were collected and converted into multiples of C4 reference range. Next generation sequencing was performed and the exons with adjacent 50 bp regions of ACAD8 and ACADS genes were captured by liquid phase capture technique. Variant information was obtained by bioinformatic analysis and the pathogenicity were classified according to the American College of Medical Genetics and Genomics criteria. The Wilcoxon rank sum test was used to analyze the differences in C4 levels among neonates with different variation types.@*RESULTS@#In total, 32 variants in ACAD8 gene were detected, of which 7 variants were reported for the first time; while 41 variants of ACADS gene were detected, of which 17 variants have not been previously reported. There were 39 cases with ACAD8 biallelic variations and 3 cases with ACAD8 monoallelic variations; 34 cases with ACADS biallelic variations and 36 cases with ACADS monoallelic variations. Furthermore, 5 cases were detected with both ACAD8 and ACADS gene variations. Inter group comparison showed that the multiples of C4 reference range in initial screening and re-examination of the ACAD8 biallelic variations and ACADS biallelic variations groups were significantly higher than those of the ACADS monoallelic variations group (all P<0.01), while the multiples in the ACAD8 biallelic variations group were significantly higher than those in the ACADS biallelic variations group (all P<0.01). The multiples of C4 reference range in the initial screening greater than 1.5 times were observed in all neonates carrying ACAD8 or ACADS biallelic variations, while only 25% (9/36) in neonates carrying ACADS monoallelic variations.@*CONCLUSIONS@#ACAD8 and/or ACADS gene variants are the main genetic causes for elevated C4 in newborns in Zhejiang region with high genotypic heterogeneity. The C4 levels of neonates with biallelic variations are significantly higher than those of neonates with monoallelic variations. The cut-off value for C4 level could be modestly elevated, which could reduce the false positive rate in tandem mass spectrometry neonatal screening.

Progress of newborn screening in China / 浙江大学学报·医学版

Newborn screening (NBS) plays a significant role in reducing the risk of birth defects. NBS in China began in the early 1980s. Under the protection of laws and regulations and the leadership of the national health administration, approved screening centers in public hospitals took the responsibility for publicity, screening, diagnosis, treatment, follow-up and management of birth defects. As of 2022, 31 provinces (autonomous regions and municipalities directly under the central government) have carried out NBS for phenylketonuria, congenital hypothyroidism, and hearing loss, 23 provinces have carried out screening for glucose-6-phosphate dehydrogenase (with a screening rate of 89.24%), and 24 provinces have carried out screening for congenital adrenal cortical hyperplasia (91.45% screening rate). Over the past four decades, screening techniques have evolved from bacterial inhibition, fluorescence analysis, and tandem mass spectrometry for the detection of biochemical markers to genetic testing, which has greatly contributed to the expansion of the types of diseases screened for. The combined use of metabolomics and genomics is currently being explored. Effective management and rigorous quality control of NBS are prerequisites for improving the quality and ensuring the accuracy of screening. The Quality Management System for Newborn Screening System Network (QMS-NBS), established by the National Center for Clinical Laboratories, covers all screening centers and related blood collection agencies. The operation of the QMS-NBS allows the quality and performance of screening to be transparent and measurable, ensuring the quality and efficiency of screening. This article provides an overview of the history of NBS, especially the evolution of policies for the NBS in China, the construction of screening institutions, the number of newborns screened, the incidence rates of screened diseases, the changes in screening technology, the expansion of new diseases screened for, and the quality control of NBS. Overall, the progress in NBS in China has not only benefited from the development and standardization at the technological level, but also benefited from the construction of policies, regulations and ethics.

A multi-center study of biochemical and hotspot gene screening for neonatal genetic metabolic diseases / 中华实用儿科临床杂志

Objective:To investigate the efficiency of biochemical screening and hotspot gene screening in the detection of neonatal inherited metabolic diseases.Methods:This was a prospective multi-center study.The study was carried out on 21 442 neonatal samples collected from 12 hospitals in 10 provinces from November 2020 to November 2021.The results of biochemical screening and hotspot gene screening were analyzed jointly.Biochemical screening methods included glucose-6-phosphate dehydrogenase deficiency enzyme activity assay and neonatal tandem mass spectrometry.Genetic screening analysis involved 135 genes associated with 75 neonatal diseases.Results:Of all the 21 442 neonates enrolled in the study, 21 205 were subject to biochemical screening.A total of 813 cases were positive in the initial screening, and 0.45% of them (95 cases) were diagnosed after recall.All the 21 442 neonates underwent gene screening.About 168 positive cases were detected in the initial screening, and 0.73% (156 cases) of them were confirmed finally.Biochemical and genetic screening improved the detection sensitivity of such diseases as primary carnitine deficiency, neonatal intrahepatic cholestasis caused by citrin deficiency, and 2-methylbutyrylglycinemia.Moreover, biochemical and genetic screening enabled the detection of more diseases, including the common single-gene genetic diseases such as thalassemia and Wilson disease.Conclusions:In neonatal screening, the combination of biochemical screening and gene screening expands the number of diseases detected and improve screening efficiency.

Newborn screening for ornithine transcarbamylase deficiency in Zhejiang Province and the follow-up analysis / 中华实用儿科临床杂志

Objective:To investigate the incidence, clinical characteristics and prognosis of ornithine transcarbamylase deficiency(OCTD) in newborns in Zhejiang Province.Methods:A retrospective research was conducted.A total of 4 261 036 newborns from Department of Genetics and Metabolism, Children′s Hospital, Zhejiang University School of Medicine, between January 2009 and December 2021 were screened for inherited metabolic disorders using tandem mass spectrometry.OCTD was confirmed by urine organic acid and OTC gene analysis.Patients with OTCD received guidance on diet and lifestyle management, and were treated with citrulline and arginine.Long-term follow-up was performed.Their growth and intellectual development were evaluated. Results:A total of 7 patients with OCTD were diagnosed, with an incidence of 1.6/1 million.All patients were males.Two patients had neonatal-onset OCTD, and the other 5 had late-onset OCTD.Symptoms occurred several times in 6 patients, inducing hyperammonemia and hepatic impairment.One patient had no clinical manifestation.One patient died in the neonatal period.Blood citrulline levels were decreased in 7 patients to varying degrees.Uracil levels were increased in 4 patients, and 1 of them was complicated with elevated orotic acid levels.All patients had hemizygote variations in the OTC gene, including 6 missense variations(c.604C>T, c.386G>A, c.779T>C, c.1019C>T, c.594C>G, c.931G>A) and 1 intron variation(c.514-35C>G). Two variants(c.594C>G, c.514-35C>G) were never reported previously. Conclusions:The OTCD incidence by newborn screening is low with 1.6/1 million in Zhejiang province.All patients are males and present hypocitrullinemia.The clinical manifestations of OTCD are highly heterogeneous.The neonatal-onset form is severe and survivors always suffer serious sequelae.The late-onset form is mostly manifested with hyperammonemia and hepatic impairment.There may be association between phenotype and genotype.Two novel OTC variants are identified, which further expands the mutational spectrum.

Genetic analysis of neonates with abnormal isovaleryl carnitine metabolism / 中华实用儿科临床杂志

Objective:To explore the genetic causes of abnormal isovaleryl carnitine (C5) metabolism in newborns.Methods:Retrospective study.The screening and clinical follow-up data of 34 neonates with elevated C5 levels shown by the tandem mass spectrometry test in Children′s Hospital, Zhejiang University School of Medicine from January 2018 to December 2021 were collected.Afterwards, their ethylenediaminetetraacetic acid (EDTA) anticoagulant venous blood was collected to extract genomic DNA.A total of 79 genes related to genetic metabolic diseases, such as ACADSB, IVD and ACADM, were captured by liquid-phase capture technology.High-throughput sequencing and bioinformatics analysis were used to acquire gene variation information and the genes were categorized by American College of Medical Genetics and Genomics classification standard.According to the results of genetic analysis, the newborns with C5 elevation were divided into 3 groups: non-mutation group(11 cases), ACADSB mutation group(16 cases) and IVD mutation group(7 cases). Wilcoxon rank sum test was performed to analyze the difference between these groups. Results:Among 34 neonates, 6 ACADSB variants were detected in 16 cases, and 2 of them [c.461G>A (p.G154E), c.746delC(p.P249Lfs*15)] were novel variants.Eleven IVD variants were detected in 7 cases, and 7 of them [c.118A>G(p.N40D), c.296-10C>G, c.302A>G(p.Y101C), c.537G>A(p.M179I), c.667C>T(p.R223W), c.983A>G(p.K328R), c.1147+ 5G>A] were never reported before.There was no significant difference in the C5 concentration in initial screening among the three groups ( P>0.05). Conclusions:Mutations in ACADSB and IVD genes are the main causes of augmented C5 levels in neonatal screening.For newly discovered genetic variants, functional prediction by multiple bioinformatics analysis software is recommended.And it is also important to carry out clinical follow-up and evaluation.

Genotypes of neonatal inherited metabolic diseases in Zhejiang Provincefrom 2009 to 2021 / 预防医学

Objective@#To investigate the genotypes and prognosis of infants with definitive diagnosis of inherited metabolic diseases during neonatal screening in Zhejiang Province from 2009 to 2021, so as to provide insights into the management of birth defects.@*Methods@#The medical records of infants with definitive diagnosis of inherited metabolic diseases by tandem mass spectrometry during neonatal screening in Zhejiang Province from 2009 to 2021 were collected from the database created by Zhejiang Provincial Center for Neonatal Disease Screening. The prevalence, genotypes and prognosis of inherited metabolic diseases were analyzed. @*Results@#A total of 1 038 infants were definitively diagnosed with inherited metabolic diseases in Zhejiang Province from 2009 to 2021, with an overall incidence rate of 1/4 535. There were 400 infants with amino acid metabolic disorders (AAD), 342 infants with fatty acid oxidation metabolic disorders and 296 infants with organic acid metabolic disorders (OAD), with incidence of 1/11 767, 1/13 763 and 1\15 902, respectively. There were 32 types of diseases, including 13 types of AAD, 8 types of FAOD and 11 types of OAD identified, and phenylketonuria and tetrahydrobiopterin deficiency (PKU/BH4D), primary carnitine deficiency (PCD) and methylmalonic academia (MMA) were detected as the most common forms of AAD, FAOD and OAD, with incidence of 1/20 827, 1/24 262 and 1\49 030, respectively. A total of 789 infants received genetic testing (76.01%), and genetic testing was performed among 70.00% of infants with AAD, 83.04% of infants with FAOD and 76.01% of infants with OAD. The c.728G >A (p.R243Q) variant was the most common mutation in infants with PKU (29.17%), c.1400C>G (p.S467C) variant was the most common mutation in infants with PCD (33.46%), c.609G>A (p.W203X) variant was the most common mutation in infants with combined MMA (40.00%), and c.1663G>A (p.A555T) variant was the most common mutation in infants with MMA (17.86%). Among the 997 infants (96.05%) with successful follow-up, 973 infants (93.74%) had normal intelligence and physical developments, and 41 infants died (3.95%), including 9 deaths due to AAD, 15 deaths due to FAOD and 17 deaths due to OAD. @*Conclusions @#The incidence of PKU, PCD and MMA was high among infants with inherited metabolic diseases in Zhejiang Province from 2009 to 2021, with c.728G>A (p.R243Q), c.1400C>G (p.S467C) and c.609G>A (p.W203X) variants as common gene mutations, respectively. Most infants with inherited metabolic diseases had a favorable prognosis; however, the mortality of OAD was relatively high.

Quality evaluation of tandem mass spectrometry screening for neonatalinherited metabolic diseases in Zhejiang Province from 2009 to 2021 / 预防医学

Objective@#To evaluate the quality of tandem mass spectrometry (MSMS) screening for neonatal inherited metabolic diseases in Zhejiang Province from 2009 to 2021.@*Methods@#The data pertaining to MSMS screening for neonatal inherited metabolic diseases in Zhejiang Province from 2009 to 2021 were collected from the database created by Zhejiang Provincial Center for Neonatal Disease Screening. The percentage of MSMS screening, percentage of recall of suspected screening-positive infants and incidence of neonatal inherited metabolic diseases were analyzed retrospectively to evaluate the quality of MSMS screening for inherited metabolic diseases.@*Results@#A total of 4 706 916 newborns were screened among 8 297 039 live births by MSMS in Zhejiang Province from 2009 to 2021, and the percentage of MSMS screening increased from 5.48% to 97.54%, with a mean percentage of 56.73%. Of 46 838 suspected screening-positive infants, 45 527 infants were recalled, and the percentage of recall increased from 94.57% to 98.62%, with a mean percentage of 97.20%. A total of 1 038 infants were definitively diagnosed with inherited metabolic diseases in Zhejiang Province from 2009 to 2021, with an overall incidence rate of 1/4 535, and the incidence rates of amino acid metabolic disorder, fatty acid oxidation metabolic disorder and organic acid metabolic disorder were 1/11 767, 1/13 763 and 1\15 902, respectively. Of the 11 cities in Zhejiang Province, the highest percentage of tandem mass spectrometry screening for inherited metabolic diseases was found in Hangzhou City (83.01%), and the highest percentage of recall of suspected screening-positive infants was se en in Zhoushan City (99.08%). @*Conclusions@#A high percentage of MSMS screening for neonatal inherited metabolic diseases was observed in Zhejiang Province from 2009 to 2021; however, there was a region-specific percentage of screening, and the recall of suspected screening-positive infants remains to be improved.

Quality monitoring and evaluation of neonatal diseasescreening in Zhejiang Province / 预防医学

Abstract@#Neonatal disease screening is a major tool for prevention of birth defects, and monitoring and evaluation of neonatal disease screening facilitates the improvements in screening quality and efficiency. A strict quality control of screening, diagnosis, treatment and follow-up of neonatal diseases is performed in Zhejiang Provincial Center for Quality Control of Neonatal Disease Screening. In this study, the data pertaining to screening of neonatal inherited metabolic diseases, hearing loss and congenital heart diseases were collected in Zhejiang Province from 2018 to 2020, and the screening rate, recall rate of suspected screening-positive neonates, and detection rate of diseases were calculated to assess the quality of neonatal disease screening. The screening rate and recall rate of neonatal inherited metabolic diseases, hearing loss and congenital heart diseases were high in Zhejiang Province, and the detection of screened diseases was stable, indicating a high overall quality of neonatal disease screening. Increasing the impact of neonatal disease screening and consolidating the screening achievements should be given a high priority during the future quality control of neonatal disease screening in Zhejiang Province.

Application of cold chain positioning system in transport of neonatal inherited metabolic disease screening samples / 预防医学

Abstract@#Transport of filter paper-dried blood spot samples is a critical procedure during the screening of neonatal inherited metabolic diseases, which is of great significance for the screening accuracy. In order to ensure the timing and safety of sample transport, the cold chain positioning system was initiated by Zhejiang Provincial Center for Quality Control of Neonatal Disease Screening since March 2015. Based on the framework of neonatal disease screening information management system, the function of the logistics transport management system was included in this positioning system, with aims to achieve the monitoring and tracking of sample transport processes through real-time positioning of the sample transport box via China Unicom 4G logistics card and global positioning system/BeiDou Navigation Satellite System. The samples are maintained in a transport environment at 2 to 8 °C via the temperature-controlled box made of 5 °C phase-changed cold-stored materials and general packet radio service (GPRS) temperature recorders. The mean pretest turnover duration reduced from 8.44 days to 5.03 days following introduction of the cold chain positioning system, and the percentage of timely sample delivery increased from 31.69% to 77.90%, while the withdrawal rate of unqualified samples reduced from 0.12% to 0.08%. The cold chain positioning system meets the requirements of transport of filter paper-dried blood spot samples, which has a high potential in screening of neonatal inherited metabolic diseases.

Application of Region 4 Stork system in the neonatal screening for very long chain acyl-CoA dehydrogenase deficiency by tandem mass spectrometry / 中华检验医学杂志

Objective:To investigate the application feasibility of Region 4 Stork (R4S) system, an international collaborative newborn screening data platform, combined with cut-off value analysis in the neonatal screening for very long chain acyl-CoA dehydrogenase deficiency (VLCADD) by tandem mass spectrometry (MS/MS).Methods:The retrospective study was performed in 2, 040 072 neonates screened by MS/MS in Neonatal Screening Center of Zhejiang Province, China from October 2013 to July 2018. Nine hundred and ten cases were determined and identified as suspected positive VLCADD neonates by traditional cut-off method of tandem mass spectrometry. The original data of these 910 screened neonates were further analyzed by R4S system. Based on clinical diagnosis and ACADL gene test results, the screening efficiency between two methods was statistically compared.Results:The data of 910 suspected VLCADD-positive cases interpreted by cut-off method were further analyzed by R4S system, and the positive interpretation was reduced to 238 cases (including 9 confirmed positive cases). A total of 16 different mutations were found in ACADL gene sequencing among the confirmed children. The screening false positive rate (FPR) declined from 0.44‰ (901/2 040 072) to 0.11‰ (229/2 040 072), the rate of positive predictive value (PPV) increased from 0.99% (9/910) to 3.78% (9/238), and the specificity increased from 99.96% (2 039 162/2 040 063) to 99.99% (2 039 834/2 040 063). There was a statistically significant difference between cut-off method alone and cut-off method combined R4S system analysis (χ2=393.5, P<0.05). Conclusions:The R4S system combined with cut-off method applied in VLCADD neonatal screening by MS/MS can effectively improve screening performance, reduce false positive rate, and has certain value in clinical application.

Screening and clinical analysis of isovaleric acidemia newborn in Zhejiang province / 浙江大学学报·医学版

OBJECTIVE@#To investigate the incidence,clinical,biochemical and genetic characteristics of isovaleric acidemia (IVA) in Zhejiang province.@*METHODS@#Between January 2009 and December 2019, a total of 3 510 004 newborns were screened for IVA using tandem mass spectrometry. Patients of IVA were confirmed by urine organic acid and @*RESULTS@#A total of 15 patients with IVA were diagnosed, with an incidence of 1/234 000. Three patients had acute neonatal IVA, and the rest were asymptomatic. The isovalerylcarnitine (C5) levels were increased in all patients. Twelve children underwent urinary organic acid analysis, of which 11 cases had elevated isovalerylglycine levels, 4 cases with 3-hydroxyisovalerate increased simultaneously. Eleven IVA patients underwent genetic testing, 9 patients were compound heterozygous variants in @*CONCLUSIONS@#The clinical manifestations of IVA are non-specific, and the gene spectrum is scattered. Newborn patients screened by tandem mass spectrometry can receive early diagnosis and treatment, so as to correct metabolic defects and pathophysiological changes.

Effects of delivery and storage conditions on concentrations of amino acids and carnitines in neonatal dried blood spots / 浙江大学学报·医学版

OBJECTIVE@#To explore effects of different delivery and storage conditions on concentrations of amino acids and carnitines in neonatal dried blood spots (DBS), so as to provide evidence for improving accurate and reliable detection by tandem mass spectrometry.@*METHODS@#A total of 1 254 616 newborn DBS samples in Newborn Screening Center of Zhejiang Province were delivered and stored at room temperature (group A, @*RESULTS@#The concentrations of amino acids and carnitines in the three groups were skewed, and the differences in amino acid and carnitine concentrations among groups were statistically significant (all @*CONCLUSIONS@#Cold-chain logistics system and storage in low temperature and low humidity can effectively reduce degradation of some amino acids and carnitines in DBS, improve the accuracy and reliability of detection, and thus ensures the quality of screening for neonatal metabolic diseases.

Identification of a de novo missense variant of ARID1B gene in a child with mental retardation / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a child with mental retardation.@*METHODS@#The child was subjected to next generation sequencing (NGS). Candidate variant was analyzed with bioinformatic software.@*RESULTS@#NGS revealed that the child has carried a de novo heterozygous c.4035G>C (p.Gln1345His) variant of the ARID1B gene. The variant was unreported previously and may cause instability of the protein structure.@*CONCLUSION@#The de novo missense variant of ARID1B gene may underlie the mental retardation in the child. Above result has enabled genetic counseling and prenatal diagnosis for her family.

Phenotypic and genetic analysis of a child with multiple malformations due to 10p13p15.3 duplication / 中华医学遗传学杂志

OBJECTIVE@#To explore the basis for a child with multiple malformations and correlate her genotype with phenotype.@*METHODS@#The child was subjected to G-banding chromosomal analysis first, and low-coverage massively parallel copy number variation sequencing (CNV-seq) was used to define the aberrant region. The results were verified by fluorescence in situ hybridization (FISH).@*RESULTS@#The child was found to have a karyotype of 46,XX,3pter+?. CNV-seq has identified a 13.5 Mb duplication at 10p13p15.3(60 466-13 556 655) and a 636 kb microdeletion at 3p26.3 (60 064-695 821). Her karyotype was the refore specified as 46, XX, ish der(3) t(3;10) (10p+,3pdim) by FISH. Both of her parents were normal, which suggested an de novo origin of the above variant.@*CONCLUSION@#The de novo 10p13p15.3 duplication probably underlies the mental retardation, development delay, dysmorphism, and gastroesophageal reflux in the child. The CHL1 gene from the 3p26.3 region may play an important role in the formation and function of the brain, which may underlie the intellectual deficit in this child.

A survey for screening situation of glucose-6-phosphate deficiency in Zhejiang province / 临床检验杂志

Objective@#To explore the epidemiological distribution characteristics of glucose-6-phosphate dehydrogenase (G6PD) activity, incidence of G6PD deficiency in neonates and the cut-off values. @*Methods@#About 1.44 million newborns in 10 districts of Zhejiang province from March 2015 to September 2017 were included in this study. Fluorescence analysis was used to determine the G6PD activity in dried blood spots. Those with initial screening positive results were recalled and confirmed by direct ratio of G6PD to 6PGD (6-phosphogluconate dehydrogenase) to confirm the diagnosis. The results were analyzed by using nonparametric and chi-square tests. @*Results@#Significant differences of G6PD levels were found among the groups of different genders, gestational age, birth weight, blood sampling age, blood sampling season and districts (P＜0.01). The male incidence of G6PD deficiency was significantly higher than female incidence. In different regions of Zhejiang province, the highest prevalence was in Lishui (0.38%) and the lowest was in Zhoushan (0.11%), The trend of high prevalence in the south and low prevalence in the north was basically showed. When the cut-off value of G6PD activity ranged from 2.60 to 2.80 U/g Hb, the sensitivity of G6PD deficiency screening for male and female newborns was 100% and the Youden index was the highest (about 0.99). @*Conclusion@#The level of G6PD activity may be relevant to the factors of population group and period. The incidence of G6PD deficiency may be affected by different genders and different regions. The cut-off values for screening may initially set at 2.60 U/g Hb and 2.80 U/g Hb for male and female respectively.