scholarly journals Somatic Variation as an Incidental Finding in the Pediatric Next Generation Sequencing Era

2021 ◽  
pp. mcs.a006135
Author(s):  
Marilena Melas ◽  
Mariam T Mathew ◽  
Mari Mori ◽  
Vijayakumar Jayaraman ◽  
Sarah A Wilson ◽  
...  

The methodologic approach used in next-generation sequencing (NGS) affords a high depth of coverage in genomic analysis. Inherent in the nature of genomic testing, there exists potential for identifying genomic findings that are incidental or secondary to the indication for clinical testing, with the frequency dependent on the breadth of analysis and the tissue sample under study. The interpretation and management of clinically meaningful incidental genomic findings is a pressing issue particularly in the pediatric population. Our study describes a 16-month old male who presented with Dandy-Walker malformation, metopic craniosynostosis and developmental delay. Clinical exome sequencing (ES) trio analysis revealed the presence of two variants in the proband. The first was a de novo variant in the PPP2R1A gene (c.773G>A, p.Arg258His), which is associated with autosomal dominant (AD) intellectual disability, accounting for the proband's clinical phenotype. The second was a recurrent hotspot variant in the CBL gene (c.1111T>C, p.Tyr371His), which was present at a variant allele fraction of 11%, consistent with somatic variation in the peripheral blood sample. Germline pathogenic variants in CBL are associated with AD Noonan syndrome-like disorder with or without juvenile myelomonocytic leukemia (JMML). Molecular analyses using a different tissue source, buccal epithelial cells, suggest that the CBL alteration may represent a clonal population of cells restricted to leukocytes. This report highlights the laboratory methodologic and interpretative processes and clinical considerations in the setting of acquired variation detected during clinical ES in a pediatric patient.

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S236-S237
Author(s):  
Nanda Ramchandar ◽  
Jessica Burns ◽  
Andrew Pennock ◽  
Christopher R Cannavino ◽  
Lauge Farnaes

Abstract Background Osteoarticular infections are often encountered in the pediatric population. Therapy is guided by isolation of a putative organism, however, operative cultures are often negative. Next generation sequencing (NGS) allows for more sensitive sampling of body compartments generally considered sterile. We sought to evaluate the utility of NGS in comparison to culture in detecting a pathogenic organism in acute osteomyelitis and septic arthritis in children. Methods This was a single-site study to evaluate the utility of NGS in comparison to culture in detecting a pathogenic organism in acute osteomyelitis and septic arthritis in children. Eligible patients were all patients with osteomyelitis or septic arthritis admitted to Rady Children’s Hospital from July 2019 through July 2020. We excluded any patients with bone or joint surgery within 30 days prior to admission. Operative samples were chosen at the surgeon’s discretion (joint aspirate, synovium, or bone) based on operative findings. We compared NGS testing to standard care culture from the same site. Results We enrolled 41 subjects. NGS of the operative samples identified a pathogen in 26 (63.4%) patients versus 18 (43.9%) by culture. Operative culture missed the diagnosis in 10 cases, though PCR identified the organism in 6 of those cases (5 were cases in which Kingella kingae was identified). In 4 subjects, NGS identified a putative organism where standard care testing (either PCR or culture) was negative. NGS was falsely positive in 1 subject and falsely negative for one other subject. Sensitivity was 96.3% (CI 95%, 81.0–99.9%) and Specificity was 92.9% (CI 95%, 66.1–99.8) for NGS versus 64.3% (CI 95%, 44.1–81.4) and 84.6% (CI 95%, 54.6–99.9%) for culture respectively. Conclusion In this single site prospective study of pediatric osteoarticular infections, we demonstrate improved sensitivity and specificity of NGS testing when compared to standard culture. Disclosures All Authors: No reported disclosures


Author(s):  
Takuya Shimizu ◽  
Tadakazu Kondo ◽  
Yasuhito Nannya ◽  
Mizuki Watanabe ◽  
Toshio Kitawaki ◽  
...  

2014 ◽  
Vol 12 (S1) ◽  
pp. S83-S86 ◽  
Author(s):  
Yul-Kyun Ahn ◽  
Swati Tripathi ◽  
Young-Il Cho ◽  
Jeong-Ho Kim ◽  
Hye-Eun Lee ◽  
...  

Next-generation sequencing technique has been known as a useful tool for de novo transcriptome assembly, functional annotation of genes and identification of molecular markers. This study was carried out to mine molecular markers from de novo assembled transcriptomes of four chilli pepper varieties, the highly pungent ‘Saengryeg 211’ and non-pungent ‘Saengryeg 213’ and variably pigmented ‘Mandarin’ and ‘Blackcluster’. Pyrosequencing of the complementary DNA library resulted in 361,671, 274,269, 279,221, and 316,357 raw reads, which were assembled in 23,607, 19,894, 18,340 and 20,357 contigs, for the four varieties, respectively. Detailed sequence variant analysis identified numerous potential single-nucleotide polymorphisms (SNPs) and simple sequence repeats (SSRs) for all the varieties for which the primers were designed. The transcriptome information and SNP/SSR markers generated in this study provide valuable resources for high-density molecular genetic mapping in chilli pepper and Quantitative trait loci analysis related to fruit qualities. These markers for pepper will be highly valuable for marker-assisted breeding and other genetic studies.


2021 ◽  
Author(s):  
Yun-Ching Chen ◽  
Fayaz Seifuddin ◽  
Cu Nguyen ◽  
Zhaowei Yang ◽  
Wanqiu Chen ◽  
...  

AbstractCopy number variation (CNV) is a common type of mutation that often drives cancer progression. With advances in next-generation sequencing (NGS), CNVs can be detected in a detailed manner via newly developed computational tools but quality of such CNV calls has not been carefully evaluated. We analyzed CNV calls reported by 6 cutting-edge callers for 91 samples which were derived from the same cancer cell line, prepared and sequenced by varying the following factors: type of tissue sample (Fresh vs. Formalin Fixed Paraffin Embedded (FFPE)), library DNA amount, tumor purity, sequencing platform (Whole-Genome Sequencing (WGS) versus Whole-Exome Sequencing (WES)), and sequencing coverage. We found that callers greatly determined the pattern of CNV calls. Calling quality was drastically impaired by low purity (<50%) and became variable when WES, FFPE, and medium purity (50%-75%) were applied. Effects of low DNA amount and low coverage were relatively minor. Our analysis demonstrates the limitation of benchmarking somatic CNV callers when the real ground truth is not available. Our comprehensive analysis has further characterized each caller with respect to confounding factors and examined the consistency of CNV calls, thereby providing guidelines for conducting somatic CNV analysis.


BMC Genomics ◽  
2018 ◽  
Vol 19 (1) ◽  
Author(s):  
Louis T. Dang ◽  
Markus Tondl ◽  
Man Ho H. Chiu ◽  
Jerico Revote ◽  
Benedict Paten ◽  
...  

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