A universal primer-independent next-generation sequencing approach for investigations of norovirus outbreaks and novel variants

Next-generation sequencing is transforming our understanding of human genetic variation but assessing the functional impact of novel variants presents challenges. We analyzed missense variants in the integrin αIIbβ3 receptor subunit genes ITGA2B and ITGB3 identified by whole-exome or -genome sequencing in the ThromboGenomics project, comprising ∼32,000 alleles from 16,108 individuals. We analyzed the results in comparison with 111 missense variants in these genes previously reported as being associated with Glanzmann thrombasthenia (GT), 20 associated with alloimmune thrombocytopenia, and 5 associated with aniso/macrothrombocytopenia. We identified 114 novel missense variants in ITGA2B (affecting ∼11% of the amino acids) and 68 novel missense variants in ITGB3 (affecting ∼9% of the amino acids). Of the variants, 96% had minor allele frequencies (MAF) < 0.1%, indicating their rarity. Based on sequence conservation, MAF, and location on a complete model of αIIbβ3, we selected three novel variants that affect amino acids previously associated with GT for expression in HEK293 cells. αIIb P176H and β3 C547G severely reduced αIIbβ3 expression, whereas αIIb P943A partially reduced αIIbβ3 expression and had no effect on fibrinogen binding. We used receiver operating characteristic curves of combined annotation-dependent depletion, Polyphen 2-HDIV, and sorting intolerant from tolerant to estimate the percentage of novel variants likely to be deleterious. At optimal cut-off values, which had 69–98% sensitivity in detecting GT mutations, between 27% and 71% of the novel αIIb or β3 missense variants were predicted to be deleterious. Our data have implications for understanding the evolutionary pressure on αIIbβ3 and highlight the challenges in predicting the clinical significance of novel missense variants.

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The utility of next-generation sequencing technologies in diagnosis of Mendelian mitochondrial diseases and reflections on clinical spectrum

Journal of Pediatric Endocrinology and Metabolism ◽

10.1515/jpem-2020-0410 ◽

2021 ◽

Vol 34 (4) ◽

pp. 417-430

Author(s):

Melis Kose ◽

Esra Isik ◽

Ayça Aykut ◽

Asude Durmaz ◽

Engin Kose ◽

...

Keyword(s):

Next Generation Sequencing ◽

Exome Sequencing ◽

Diagnostic Process ◽

Unknown Etiology ◽

Next Generation ◽

Related Gene ◽

Targeted Exome Sequencing ◽

Novel Variants ◽

Gene Defects ◽

Generation Sequencing

Abstract Objectives Diagnostic process of mitochondrial disorders (MD) is challenging because of the clinical variability and genetic heterogeneity of these conditions. Next-Generation Sequencing (NGS) technology offers a high-throughput platform for nuclear MD. Methods We included 59 of 72 patients that undergone WES and targeted exome sequencing panel suspected to have potential PMDs. Patients who were included in the analysis considering the possible PMD were reviewed retrospectively and scored according to the Mitochondrial Disease Criteria Scale. Results Sixty-one percent of the patients were diagnosed with whole-exome sequencing (WES) (36/59) and 15% with targeted exome sequencing (TES) (9/59). Patients with MD-related gene defects were included in the mito group, patients without MD-related gene defects were included in the nonmito group, and patients in whom no etiological cause could be identified were included in the unknown etiology group. In 11 out of 36 patients diagnosed with WES, a TES panel was applied prior to WES. In 47 probands in 39 genes (SURF1, SDHAF1, MTO1, FBXL4, SLC25A12, GLRX5, C19oRF12, NDUFAF6, DARS2, BOLA3, SLC19A3, SCO1, HIBCH, PDHA1, PDHAX, PC, ETFA, TRMU, TUFM, NDUFS6, WWOX, UBCD TREX1, ATL1, VAC14, GFAP, PLA2G6, TPRKB, ATP8A2, PEX13, IGHMBP2, LAMB2, LPIN1, GFPT1, CLN5, DOLK) (20 mito group, 19 nonmito group) 59 variants (31 mito group, 18 nonmito group) were detected. Seven novel variants in the mito group (SLC25A12, GLRX5, DARS2, SCO1, PC, ETFA, NDUFS6), nine novel variants in the nonmito group (IVD, GCDH, COG4, VAC14, GFAP, PLA2G6, ATP8A2, PEX13, LPIN1) were detected. Conclusions We explored the feasibility of identifying pathogenic alleles using WES and TES in MD. Our results show that WES is the primary method of choice in the diagnosis of MD until at least all genes responsible for PMD are found and are highly effective in facilitating the diagnosis process.

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A comparison between next-generation sequencing and ASO-qPCR for minimal residual disease detection in multiple myeloma.

Journal of Clinical Oncology ◽

10.1200/jco.2013.31.15_suppl.8601 ◽

2013 ◽

Vol 31 (15_suppl) ◽

pp. 8601-8601

Author(s):

Hiroyuki Takamatsu ◽

Ryoichi Murata ◽

Jianbiao Zheng ◽

Martin Moorhead ◽

Yasushi Terasaki ◽

...

Keyword(s):

Multiple Myeloma ◽

Next Generation Sequencing ◽

Minimal Residual Disease ◽

Residual Disease ◽

Survival Rates ◽

Japanese Patients ◽

Next Generation ◽

Universal Primer ◽

Generation Sequencing ◽

Minimal Residual

8601 Background: Although molecular CR in multiple myeloma (MM) can be assessed by allele-specific oligonucleotide (ASO)-PCR, this technique requires preparation of clonotype-specific primers for each individual which is laborious and time-consuming. The usage of the LymphoSIGHT method, a next-generation sequencing (NGS)-based platform, may overcome these challenges and increase sensitivity and specificity. We compared the LymphoSIGHT approach with ASO-qPCR for minimal residual disease (MRD) detection in autografts in the autologous peripheral blood stem cell transplantation (ASCT) setting. Methods: Seventeen Japanese patients with newly diagnosed MM who received various induction regimens prior to ASCT were retrospectively analyzed. All patients had achieved a PR or CR after ASCT. Bone marrow (BM) slides from 13 MM patients and fresh BM cells from 4 MM patients at diagnosis as well as autografts were obtained for DNA extraction. Using universal primer sets, we amplified IGH variable (V), diversity (D), and joining (J) gene segments, IGH-DJ, and IGK from genomic DNA. Amplified products were subjected to deep sequencing using NGS. Reads were analyzed using standardized algorithms for clonotype determination. Myeloma-specific clonotypes were identified for each patient based on their high frequency in BM samples. The presence of the myeloma clonotype was then assessed in follow-up samples. Results: MRD in autografts was detected in 6 of 17 (35%) by ASO-qPCR and 13 of 17 (76%) by NGS. When MRD was assessed by NGS, 6 MRD (+) cases received post-ASCT therapy while 4 MRD (-) cases and 7 MRD (+) cases were followed without post-ASCT therapy. The MRD (-) cases tended to show a better PFS than the MRD (+) cases with post-ASCT therapy (P = 0.26) and those without post-ASCT therapy (P = 0.09) although overall survival rates were comparable among the three groups. There was no difference in PFS between MRD (-) and MRD (+) cases when MRD was assessed by ASO-qPCR (P = 0.6). These studies will be extended in 30 additional MM patients, and results will be presented. Conclusions: MRD-negativity in autografts revealed by NGS may be more closely associated with durable remission of MM than that revealed by ASO-qPCR.

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