scholarly journals Quantification of Differential Metabolites in Dried Blood Spots Using Second-Tier Testing for SCADD/IBDD Disorders Based on Large-Scale Newborn Screening in a Chinese Population

2021 ◽  
Vol 9 ◽  
Author(s):  
Wei Zhou ◽  
Heng Cai ◽  
Huizhong Li ◽  
Zhe Ji ◽  
Maosheng Gu
Keyword(s):  
Newborn Screening ◽  
Large Scale ◽  
Dehydrogenase Deficiency ◽  
Clinical Performance ◽  
False Positive Rate ◽  
Dried Blood Spots ◽  
Care Hospital ◽  
Blood Spots ◽  
Metabolic Defects ◽  
Second Tier

Background: Although newborn screening (NBS) for metabolic defects using the marker butyl carnitine (C4) combined with the C4-to-acetylcarnitine ratio is adequate, the incorporation of novel parameters may improve differential testing for these disorders without compromising sensitivity.Methods: Analytical and clinical performance was evaluated by MS/MS using 237 initially positive neonatal samples between March 2019 and March 2020 at the Newborn Screening Center of Xuzhou Maternity and Child Health Care Hospital. Additionally, second-tier testing by ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) combined with the quantification of ethylmalonate (EMA) or isobutyryl-glycine (IBG) in dried blood spots (DBSs) was performed to reduce the false-positive rate.Results: We reviewed initial MS/MS data for DBSs from 469,730 neonates, and a second-tier test was performed using 237 samples that exceeded the C4 concentration cutoff value. Eleven variants of the ACADS gene were identified, with c.1031A>G (p.E344G) being the most common. Fifteen ACAD8 mutations were identified in seven patients, and Swiss modeling and amino acid conservation analyses were conducted for the novel variants. Based on a retrospective analysis of EMA and IBG, the application of second-tier tests before the release of neonatal screening results reduced referrals by over 91.89% and improved the positive predictive value (PPV) for short-chain acyl-CoA dehydrogenase deficiency/isobutyryl-CoA dehydrogenase deficiency (SCADD/IBDD) screening.Conclusion: A screening algorithm including EMA/IBG improves target differential testing for NBS and may eliminate unnecessary referrals while maintaining 100% sensitivity. Second-tier screening using UPLC-MS/MS as a rapid and convenient supplemental DNA sequencing method may be beneficial for differential detection.

scholarly journals Second-Tier Test for Quantification of Alloisoleucine and Branched-Chain Amino Acids in Dried Blood Spots to Improve Newborn Screening for Maple Syrup Urine Disease (MSUD)

2008 ◽  
Vol 54 (3) ◽  
pp. 542-549 ◽  
Author(s):  
Devin Oglesbee ◽  
Karen A Sanders ◽  
Jean M Lacey ◽  
Mark J Magera ◽  
Bruno Casetta ◽  
...  
Keyword(s):  
Amino Acids ◽  
Newborn Screening ◽  
Dried Blood Spots ◽  
Branched Chain Amino Acids ◽  
Maple Syrup ◽  
Blood Spots ◽  
Urine Disease ◽  
Second Tier ◽  
Branched Chain ◽  
Positive Results

Abstract Background: Newborn screening for maple syrup urine disease (MSUD) relies on finding increased concentrations of the branched-chain amino acids (BCAAs) leucine, isoleucine, and valine by tandem mass spectrometry (MS/MS). d-Alloisoleucine (allo-Ile) is the only pathognomonic marker of MSUD, but it cannot be identified by existing screening methods because it is not differentiated from isobaric amino acids. Furthermore, newborns receiving total parenteral nutrition often have increased concentrations of BCAAs. To improve the specificity of newborn screening for MSUD and to reduce the number of diet-related false-positive results, we developed a LC-MS/MS method for quantifying allo-Ile. Methods: Allo-Ile and other BCAAs were extracted from a 3/16-inch dried blood spot punch with methanol/H2O, dried under nitrogen, and reconstituted into mobile phase. Quantitative LC-MS/MS analysis of allo-Ile, its isomers, and isotopically labeled internal standards was achieved within 15 min. To determine a reference interval for BCAAs including allo-Ile, we analyzed 541 dried blood spots. We also measured allo-Ile in blinded samples from 16 MSUD patients and 21 controls and compared results to an HPLC method. Results: Intra- and interassay imprecision (mean CVs) for allo-Ile, leucine, isoleucine, and valine ranged from 1.8% to 7.4%, and recovery ranged from 91% to 129%. All 16 MSUD patients were correctly identified. Conclusions: The LC-MS/MS method can reliably measure allo-Ile in dried blood spots for the diagnosis of MSUD. Applied to newborn screening as a second-tier test, it will reduce false-positive results, which produce family anxiety and increase follow-up costs. The assay also appears suitable for use in monitoring treatment of MSUD patients.

Next-generation sequencing as a second-tier diagnostic test for newborn screening

2018 ◽  
Vol 31 (8) ◽  
pp. 927-931 ◽  
Author(s):  
Xiaomei Luo ◽  
Ruifang Wang ◽  
Yanjie Fan ◽  
Xuefan Gu ◽  
Yongguo Yu
Keyword(s):  
Next Generation Sequencing ◽  
Newborn Screening ◽  
Diagnostic Test ◽  
Genomic Dna ◽  
Sanger Sequencing ◽  
Dried Blood Spots ◽  
Next Generation ◽  
Blood Spots ◽  
Second Tier ◽  
Generation Sequencing

Abstract Background Tandem mass spectrometry (MS/MS) has been used for newborn screening (NBS) of inherited metabolic diseases (IMDs) for decades. However, the traditional approach can yield false-positive or false-negative results and is affected by biochemical substrate-level fluctuations. To overcome the current limitations, we explored the possibility of using next-generation sequencing (NGS) as a second-tier diagnostic test to detect gene mutations in samples with abnormal MS/MS results. Methods Genomic DNA was extracted from dried blood spots and we designed a multigene panel, comprising 77 genes related to over 40 IMDs, for NBS. The prepared libraries were sequenced on the Ion Personal Genome Machine (PGM) platform. Thirty-eight samples identified as abnormal by MS/MS were tested for the diagnostic accuracy of NGS compared with Sanger sequencing. Results The concentration of DNA extracted from the 38 dried blood spots was sufficient for library preparation. The coverage and depth of the sequencing data were sufficient for the analysis. For all samples, the NGS results were consistent with the Sanger sequencing results. Conclusions The genomic DNA extracted from dried blood spots could be used for NGS, generating reliable sequencing results, and NGS may function as a second-tier diagnostic test for NBS. Ion PGM could facilitate the molecular diagnosis of IMDs with appropriate primers designed for candidate genes.

Newborn screening for galactosemia by a second-tier multiplex enzyme assay using UPLC-MS/MS in dried blood spots

2011 ◽  
Vol 34 (2) ◽  
pp. 409-414 ◽  
Author(s):  
Dae-Hyun Ko ◽  
Sun-Hee Jun ◽  
Kyoung Un Park ◽  
Sang Hoon Song ◽  
Jin Q Kim ◽  
...  
Keyword(s):  
Newborn Screening ◽  
Enzyme Assay ◽  
Dried Blood Spots ◽  
Blood Spots ◽  
Second Tier

scholarly journals Newborn Screening for Methylmalonic Acidemia/propionic Acidemia: Systematic Evaluation of a Two-pronged Approach Based on MS/MS and UPLC-MS/MS

2021 ◽  
Author(s):  
Wei Zhou ◽  
Jinxiu Song ◽  
Huizhong Li ◽  
Zhe Ji ◽  
Xin Yin ◽  
...  
Keyword(s):  
Birth Weight ◽  
Newborn Screening ◽  
False Positive ◽  
False Positive Rate ◽  
Propionic Acidemia ◽  
Methylmalonic Acidemia ◽  
Systematic Evaluation ◽  
Care Hospital ◽  
Positive Rate ◽  
Second Tier

Abstract Background: An improved second-tier test is needed to reduce the false-positive rate of newborn screening (NBS) for inborn metabolic disorders in Xuzhou, China.Methods: We designed an expanded second-tier assay using newborn dried blood spots (DBSs). Analytical and clinical performance were evaluated in 53 newborns with methylmalonic acidemia (MMA) or propionic acidemia (PA) reported by the Xuzhou Maternity and Child Health Care Hospital NBS program. Additionally, we analyzed NBS data regarding seasonal variation of metabolites, birth weight and gestational age to improve the identification of true positive MMA/PA individuals.Results: Among the 53 MMA/PA individuals assessed, two pathogenic or likely pathogenic (P/LP) variants in an MMA/PA-associated gene were identified in 46 patients, and a pathogenic variant and a variant of unknown significance (VUS) were identified in 7 patients. No such variants were detected in MMA/PA false-positive individuals or healthy controls. Ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS)-based analysis of the initial NBS metabolic profile correctly identified MMA/PA individuals and reduced the initial NBS false-positive rate by 98.86%. MMA/PA false-positive infants in Xuzhou, China, were most likely to be summer-born.Conclusion: We established a two-pronged approach to reduce false positives by nearly 99% and provided a novel NBS strategy. Challenges in neonate metabolic testing and DNA variant interpretation regarding season, birth weight and pregnancy status remain for this Chinese population.

scholarly journals Genomic Analysis of Historical Cases with Positive Newborn Screens for Short-Chain Acyl-CoA Dehydrogenase Deficiency Shows That a Validated Second-Tier Biochemical Test Can Replace Future Sequencing

2020 ◽  
Vol 6 (2) ◽  
pp. 41
Author(s):  
Aashish N. Adhikari ◽  
Robert J. Currier ◽  
Hao Tang ◽  
Coleman T. Turgeon ◽  
Robert L. Nussbaum ◽  
...  
Keyword(s):  
Newborn Screening ◽  
Dehydrogenase Deficiency ◽  
Autosomal Recessive Disorder ◽  
Dried Blood Spots ◽  
Short Chain ◽  
Compound Heterozygous ◽  
Urine Metabolites ◽  
Chain Acyl ◽  
Second Tier ◽  
Hydroxyglutaric Acid

Short-chain acyl-CoA dehydrogenase deficiency (SCADD) is a rare autosomal recessive disorder of β-oxidation caused by pathogenic variants in the ACADS gene. Analyte testing for SCADD in blood and urine, including newborn screening (NBS) using tandem mass spectrometry (MS/MS) on dried blood spots (DBSs), is complicated by the presence of two relatively common ACADS variants (c.625G>A and c.511C>T). Individuals homozygous for these variants or compound heterozygous do not have clinical disease but do have reduced short-chain acyl-CoA dehydrogenase (SCAD) activity, resulting in elevated blood and urine metabolites. As part of a larger study of the potential role of exome sequencing in NBS in California, we reviewed ACADS sequence and MS/MS data from DBSs from a cohort of 74 patients identified to have SCADD. Of this cohort, approximately 60% had one or more of the common variants and did not have the two rare variants, and thus would need no further testing. Retrospective analysis of ethylmalonic acid, glutaric acid, 2-hydroxyglutaric acid, 3-hydroxyglutaric acid, and methylsuccinic acid demonstrated that second-tier testing applied before the release of the newborn screening result could reduce referrals by over 50% and improve the positive predictive value for SCADD to above 75%.

scholarly journals Evaluation of Multiple Methods for Quantification of Glycosaminoglycan Biomarkers in Newborn Dried Blood Spots from Patients with Severe and Attenuated Mucopolysaccharidosis-I

2020 ◽  
Vol 6 (3) ◽  
pp. 69 ◽  
Author(s):  
Zackary M. Herbst ◽  
Leslie Urdaneta ◽  
Terri Klein ◽  
Maria Fuller ◽  
Michael H. Gelb
Keyword(s):  
False Positive ◽  
Reference Range ◽  
Severe Disease ◽  
False Positive Rate ◽  
Dried Blood Spots ◽  
Mucopolysaccharidosis I ◽  
Blood Spots ◽  
Positive Rate ◽  
Second Tier ◽  
Mps I

All newborn screening (NBS) for mucopolysaccharidosis-I (MPS-I) is carried out by the measurement of α-iduronidase (IDUA) enzymatic activity in dried blood spots (DBS). The majority of low enzyme results are due to pseudodeficiencies, and studies from the Mayo Clinic have shown that the false positive rate can be greatly reduced by including a second-tier analysis of glycosaminoglycans (GAGs) in DBS as part of NBS. In the present study, we obtained newborn DBS from 13 patients with severe MPS-I and 2 with attenuated phenotypes. These samples were submitted to four different GAG mass spectrometry analyses in a comparative study: (1) internal disaccharide; (2) endogenous disaccharide; (3) Sensi-Pro; (4) Sensi-Pro Lite (a variation of Sensi-Pro with a simplified workflow). Patients with attenuated MPS-I show less GAG elevation than those with severe disease, and all MPS-I patients were separated from the reference range using all four methods. The minimal differential factor (lowest GAG marker level in MPS-I samples divided by highest level in the reference range of 30 random newborns) was about two for internal disaccharide, Sensi-Pro, and Sensi-Pro Lite methods. The endogenous disaccharide was clearly the best method with a minimal differential of 16-fold. This study supports use of second-tier GAG analysis of newborn DBS, especially the endogenous disaccharide method, as part of NBS to reduce the false positive rate.

Sign in / Sign up

Export Citation Format

Share Document