Generation Sequencing Methods Research Articles

Molecular and clinical profiles of pediatric monogenic diabetes subtypes: comprehensive genetic analysis of 138 patients.

Single gene variants that give rise to neonatal diabetes mellitus (NDM), maturity onset diabetes of the young (MODY) and syndromic forms of diabetes mellitus (SDM) are responsible for 3.1-4.2% of all diabetes cases. This single-center study with a relatively larger sample size aimed to evaluate the clinical and genetic characteristics of Chinese children with suspected monogenic diabetes (MD) using next generation sequencing (NGS) methods. Data were collected from 1550 consecutive children diagnosed with diabetes/hyperglycemia at the Endocrinology Department of Children's Hospital of Nanjing Medical University from 2012 to 2023. The genotype and phenotype of 138 children with suspected MD were retrospectively analyzed. Among 138 children, 16, 97, and 25 patients with NDM, suspected MODY and SDM were assessed by NGS, with a pick-up rate of 87.5%, 57.8%, and 56%, respectively. In total, there was a high pick-up rate of MD, with 58% (80 of 138) among antibody-negative pediatric patients. Pathogenic variants were found in GCK, HNF1A, INS, KCNJ11, INSR, HNF4A, ABCC8, WFS1, ALMS1, HNF1B, BLK and ZFP57 genes with 13 novel variants in addition to 4 patients with CNVs. In this cohort, GCK-MODY was the leading cause and the mildest type of MODY. GCK-MODY displayed favorable lipid profile when compared to non-GCK-MODY and MODYX, which might be cardioprotective. Following an accurate genetic diagnosis of diabetes, 19 patients switched from insulin therapy to oral agents or lifestyle interventions. NGS tests helped to identify the precise etiology of monogenic diabetic patients which has implications for better individualized management.

Distribution and classifications of PKHD1 gene variants in a Turkish population using the next generation sequencing method.

Autosomal recessive polycystic kidney disease is an inherited kidney disease. This study aims to detect rare and common DNA variants of the PKHD1 gene using next-generation sequencing (NGS) and to classify them in terms of being pathogenic according to The American College of Medical Genetics and Genomics. NGS analysis was performed on the DNA of 304 patients who were referred to Ege University Molecular Medicine Laboratory with suspected polycystic kidney disease. As a result, a total of 82 different DNA variants, 16 of which were novel, were detected. The breakdown of the variants found is as follows: 73 (89.02%) were missense variants, six (7.32%) nonsense variants, two (2.44%) frameshift deletions, and one (1.22%) nonframeshift deletion. According to The American College of Medical Genetics and Genomics classification of these variants, 26 were benign (Class 5), two were likely benign (Class 4), 36 were of uncertain significance (Class 3), and nine were likely pathogenic (Class 2), nine of which are pathogenic variants (Class 1). Heterozygosity was found in 39 (63.9%) patients, homozygosity in six (9.8%) patients, compound heterozygosity in 12 (19.7%) patients, and complex genotype in four (6.6%) patients in which variants in Class 1, Class 2 and Class 3 were determined according to ACMG classification. When the exon distributions of the DNA variants detected in the PKHD1 gene were analyzed, the most common exons of the DNA variant are exon 32 (n = 9), exon 58 (n = 8), exon 67 (n = 6), exon 61 (n = 5), 30 exons (n = 4). This fast and economical molecular diagnostic approach will provide a reliable prenatal diagnostic option, enabling definitive disease diagnosis and the identification of carriers.

Investigation of the effect of human intestinal microbiota bacteria on the bioremediation of commonly used pesticides by liquid chromatography

Pesticides are defined as chemical substances used to protect a variety of plants from parasite infestation. Due to their chemical structure, they have a long half-life and the capacity to form residues, and therefore many fruits can contain pesticide residues. Pesticide exposure may occur via inhalation, ingestion, or direct contact. The European Commission's directive restricts the use of pesticides and sets a residue limit of 0.1 μg/L. The aim of this study is to determine the impact of bacteria in the human gut microbiota on the biodegradation of commonly used pesticides. This study investigated the effects of five bacterial strains, namely Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae (K. pneumoniae), and Enterococcus faecalis (E. faecalis), isolated from neonatal rectal swab samples and, blood samples on the degradation of pesticides using liquid chromatography and mass spectrometry. (LC-MS). All bacteria resulted in significant pesticide degradation (p < 0.05). E. faecalis caused significantly more degradation than K. pneumoniae (p = 0.043). No significant difference was observed between the degradation rates of pesticides and other bacteria (p > 0.05). The results demonstrate that bacteria can be used to clean water and soil contaminated with pesticides. Therefore, we do not have information about possible mutations in DNA. This is the biggest limitation of this study. Therefore, our study data needs to be supported with study data including more strains and examining bacterial DNA with new generation sequencing methods.

199 Awardee Talk: Insights into translational regulation through tRNA sequencing, RNA sequencing, and ribosome profiling

Abstract Translation acts as an additional layer of regulation that has an important role in gene expression and function. Due to a phenomenon called codon usage bias, highly expressed genes are thought to be codon-biased to support efficient translation. As more than one codon can code for the same amino acid (synonymous codons), organisms may exhibit preferences for specific codons that facilitate increased expression of important genes due to variations in the availability of corresponding tRNAs. Advances in sequencing technologies have recently permitted the study of the translatome, which refers to the entire population of mRNA associated with ribosomes for protein synthesis and can be investigated through ribosome profiling. This cutting-edge technique allows the identification of actively translated regions, but can also reveal translational pausing events that stem from the presence of SNPs. Our previous research has demonstrated variation in tRNA expression across tissues and different states of health, leading us to consider the connection between tRNA abundance and translational stalling due to SNPs. By coupling ribosome profiling with tRNA sequencing and RNA sequencing, we have investigated all elements of translational machinery to predict translational efficiency, estimate proteome composition, and evaluate tRNA abundance as a source of genetic variation. In this work, we utilized ribosome profiling, tRNAseq, and RNAseq and performed an integrative analysis in bovine tissues (kidney, liver and muscle) as well as murine myoblast cell lines (C2C12). By applying these methods to different bovine tissues, we were able to explore the interplay between tRNA availability and translational stalling events. Moreover, we have identified translationally regulated genes underlying tissue-specific biological processes and found that many upregulated and downregulated genes coincided with high and low translational efficiency respectively. We have also successfully defined stalling sites that depict the regulatory information encoded within the coding sequence of transcripts, which could control translation rate and facilitate proper protein folding. Through the implementation of these next generation sequencing (NGS) methods to cell culture, we were able to evaluate the translatome at various time points (0-min, 30-min, 60-min, and 4-h) post-induction of differentiation. Where most studies have focused on molecular changes between differentiating myoblasts and multinucleated myotubes that are present 7 d after differentiation, we focus on the earliest stages of muscle differentiation that initiate muscle development and therefore kickstart the process of meat production. This work offers an atlas of distinctive stalling sites across bovine tissues and various stages of muscle differentiation, which provides an opportunity to predict codon optimality and understand tissue-specific or time-specific mechanisms of regulating protein synthesis.

Identification of HPV16 Lineages in South African and Mozambican Women with Normal and Abnormal Cervical Cytology.

Human papillomavirus 16 (HPV16) is an oncogenic virus responsible for the majority of invasive cervical cancer cases worldwide. Due to genetic modifications, some variants are more oncogenic than others. We analysed the HPV16 phylogeny in HPV16-positive cervical Desoxyribonucleic Acid (DNA) samples collected from South African and Mozambican women to detect the circulating lineages. Polymerase chain reaction (PCR) amplification of the long control region (LCR) and 300 nucleotides of the E6 region was performed using HPV16-specific primers on HPV16-positive cervical samples collected in women from South Africa and Mozambique. HPV16 sequences were obtained through Next Generation Sequencing (NGS) methods. Geneious prime and MEGA 11 software were used to align the sequences to 16 HPV16 reference sequences, gathering the A, B, C, and D lineages and generating the phylogenetic tree. Single nucleotide polymorphisms (SNPs) in the LCR and E6 regions were analysed and the phylogenetic tree was generated using Geneious Prime software. Fifty-eight sequences were analysed. Of these sequences, 79% (46/58) were from women who had abnormal cervical cytology. Fifteen SNPs in the LCR and eight in the E6 region were found to be the most common in all sequences. The phylogenetic analysis determined that 45% of the isolates belonged to the A1 sublineage (European variant), 34% belonged to the C1 sublineage (African 1 variant), 16% belonged to the B1 and B2 sublineage (African 2 variant), two isolates belonged to the D1-3 sublineages (Asian-American variant), and one to the North American variant. The African and European HPV16 variants were the most common circulating lineages in South African and Mozambican women. A high-grade squamous intraepithelial lesion (HSIL) was the most common cervical abnormality observed and linked to European and African lineages. These findings may contribute to understanding molecular HPV16 epidemiology in South Africa and Mozambique.

Investigation of Targeted Genes and Identification of Novel Variants with Next Generation Sequencing Method in Hearing Loss.

Hearing loss is a widespread condition throughout the world. It may affect patients from newborns to the elderly. There are too many reasons for hearing loss, including congenital hearing loss, virus infections, age-related situations, and traumatic situations, which may be related to the immune-mediated system. Fifty percent of hearing loss is related to genetic mutations and defects; genetic causes are highly heterogeneous, so the analysis of new variants are important for diagnosis. We aimed to describe the importance of detected gene variations by using targeted gene panels in the Next-Generation-Sequencing (NGS) platform. Eighty-one hearing loss targeted genes were investigated using Illumina NextSeq550 technology in 100 participants with hearing loss between 2017 and 2022 in our Genetic Diseases Evaluation Center. Targeted genes were performed on 100 patients with hearing loss diagnosis. The total number of detected variants was 77. Forty-seven cases have likely pathogenic/pathogenic variants. Thirty of them have uncertain clinical significance variants, and from the detected variants, 8 are novel. In this research, we highlighted that earlier detection of hearing loss using molecular genetic methods may help us understand the etiology and orient for a better prognosis. Results detected by using the NGS platform can assist and improve the diagnosis. In this study, the diagnostic rate with targeted genes was detected as 35.29%. It has an important role in clinical practice as the recommendation of cochlear implants. Clarifying the genotype and phenotype correlation helps us figure out the etiology of hearing loss and also the worth of genetic counseling in hereditary hearing loss.

O-281 Characterization of Vaginal microbiota and reproductive outcomes associated with assisted reproductive technologies through next-generation sequencing, from Indian population

Abstract Study question Is there any association between the composition of the vaginal microbiota and the reproductive outcomes in infertile women’s undergoing for assisted reproductive treatments (ART)? Summary answer Higher microbial abundance in non-pregnant patients compared to pregnant patients. These pathogens could be used as a possible marker for a higher IVF failure rate. What is known already Various next- generation sequencing methods have been used to study bacterial populations in infertile Women. Vaginal microbiota could have an influence on success rates of fertility treatments. The bacterial microbiota varies by the population. There is no direct evidence on this subject to guide clinical decision making or its influence on the hierarchy of fertility treatments. While the presence of pathogenic bacteria non-Lactobacilli dominated microbiota is associated with poor reproductive outcomes in assisted reproductive treatments (ART). Additional studies, particularly those using metagenomics approaches, may be useful. Study design, size, duration A total of 240 infertile women’s were included in the study. The study population consists of patients attending to the ART unit of a tertiary medical center Udaipur, India, between November 2021 to October 2023. Depending on the biochemical pregnancy results, they were divided into two groups. Group 1 (n = 128) was pregnancy (P), and Group 2 (n = 112) non- pregnancy (NP) group, Patients were aged between (20-45 years). The ethical approval was obtained from the institute. Participants/materials, setting, methods DNA was extracted from vaginal swab samples collected at the time of oocyte pick up using the commercially available ( DNeasy Power Soil kit). The Vaginal microbiota of samples were analyzed using 16S ribosomal RNA gene amplification (MinION) Oxford Nanopore Ltd. Bioinformatics analysis was performed using QIIME2 and Microbiome Analyst packages. Alpha, beta diversity and taxonomic characterization were compared for microbial composition. The findings of the principle coordinate analysis were shown using R version 4.0. Main results and the role of chance Our results show that higher Shannon and Simpson index were obtained in the non- pregnancy (NP) group compared to the pregnancy (P) group. In addition, the partial least squares discriminant analysis (PLS-DA) revealed a difference in microbial composition between pregnancies (P) and non- pregnancy (NP) groups, as well as a higher microbial abundance in non-pregnant patients compared to pregnant patients. At the phylum level Firmicutes, Actinobacteria, Proteobacteria, Fusobacteria, and Bacteroidetes are the most common predominant in the pregnancy (P) group (80.77, 9.52, 9.18, 0.04, and 0.40%, respectively) and the non- pregnancy (NP) group (72, 61, 12.41, 8.01, and 3.75%). A higher abundance of Firmicutes (80.77 vs. 72.61%) and Proteobacteria (9.18 vs. 8.01%), and a lower abundance of Actinobacteria (9.52 vs. 12.41%, p = 0.03), Fusobacteria (0.04 vs. 8.01%, p = 0.02), and Bacteroidetes (0.40 vs. 3.75%, p = 0.03) were observed in pregnancy (P) group. At the genus level, pregnancy group (P) increased the abundance of probiotics lactic acid bacteria (74.61 vs 63.09%) and decreased the abundance of the pathogen Gardnerella (6.03 vs 7.24%, p = 0.03), Atopobium (0.84 vs 4.14%, p = 0.02), Sneathia (0.03 vs. 3.75%, p = 0.02), and Prevotella (0.38 vs. 3, 02%, p = 0.04). Limitations, reasons for caution The limited sample size is the primary constraint of this study. Larger studies with a larger sample size are needed to confirm the distinct microbiome patterns identified in female reproductive tracts samples in connection to infertility and live birth rate (LBR) outcomes. Wider implications of the findings Vaginal microbiota composition associated to different clinical outcomes in patients undergoing ART might have profound implications. This may lead to failed fertility treatments and reduced live birth rate (LBR). More studies are needed to clarify the relative effectiveness of treatments for infertility. Trial registration number NA

Electronic Medical Record-Based Nudge Intervention to Increase Comprehensive Molecular Genotyping in Patients With Metastatic Non-Small Cell Lung Cancer: Results From a Prospective Clinical Trial.

Less than half of the patients with newly diagnosed metastatic non-small cell lung cancer (NSCLC) undergo comprehensive molecular testing. We designed an electronic medical record (EMR)-based "nudge intervention" to prompt plasma-based molecular testing at the time of initial medical oncology consultation. A nonrandomized prospective trial was conducted at the University of Pennsylvania's academic practice and two affiliated community practices. Molecular genotyping was performed by tissue- and/or plasma-based next generation sequencing methods. Comprehensive testing was defined as testing for EGFR, ALK, BRAF, ROS1, MET, RET, KRAS, and NTRK. Guideline-concordant treatment was defined as the use of the appropriate first-line (1L) therapy as per the National Comprehensive Cancer Network (NCCN) guidelines. Proportion of patients with comprehensive molecular genotyping results available at any time, molecular results available before 1L therapy, and guideline-concordant 1L treatment were compared between the preintervention and postintervention cohorts using Fisher's exact test or Pearson's chi-squared test. Five hundred and thirty-three patients were included, 376 in the preintervention cohort and 157 in the postintervention cohort. After implementation of the EMR-based nudge, a higher proportion of patients underwent comprehensive molecular testing in the postintervention versus the preintervention cohort (100% v 88%, P = <.001), had results of comprehensive molecular testing available before initiating 1L treatment (97.3% v 91.6%, P = .026), and received NCCN guideline-concordant care (89.8% v 78.2%, P = .035). Across three practice sites in a large health system, implementation of a provider team-focused EMR-based nudge intervention was feasible, and led to a higher number of patients with NSCLC undergoing comprehensive molecular genotyping. These findings demonstrate that behavioral nudges can promote molecular testing and should be studied further as a tool to improve guideline-concordant care in both community and academic sites.

An exploratory study on prediction of risk for abemaciclib-induced interstitial lung disease or hepatotoxicity by specific human leukocyte antigen alleles.

3087 Background: Interstitial lung disease (ILD) and hepatotoxicity have been observed in a small population of patients treated with abemaciclib. It has been reported that the antitumor effect of cyclin-dependent kinases 4 and 6 inhibitors including abemaciclib is contributed by not only inducing tumor cell cycle arrest but also promoting antitumor immunity. Based on our experience of higher incidence of severe toxicities in the clinical study of abemaciclib combined with nivolumab, we speculated that abemaciclib-related toxicity might also be mediated by immune system. This study sought to identify specific human leukocyte antigen (HLA) alleles associated with abemaciclib-induced ILD or hepatotoxicity. Methods: Of 236 abemaciclib-treated patients with advanced breast cancer in the previous observational study, 83 patients were enrolled by obtaining additional informed consent for collecting blood and pharmacogenetic investigation. Genomic DNA was extracted from peripheral whole blood, and HLA-A, -B, -C, -DRB1, -DQA1, -DQB1, and -DPB1were genotyped to four-digit resolution by next generation sequencing method. Exploratory marker identification evaluated the HLA alleles with frequency of ≥ 10% in cases. The significance level was adjusted by Bonferroni’s correction for multiple testing. Results: One hundred seventeen alleles ( HLA-A,13 alleles; -B, 26 alleles; -C, 16alleles; -DRB1,24 alleles; -DQA1, 14 alleles; -DQB1, 13 alleles; -DPB1, 11 alleles) were detected. Of 28 alleles with frequency of ≥ 10% in cases with development of ILD [significance level = .00178 (0.05 divided by 28)], there was no significant association between HLA allele carriages and development of ILD in 16 cases and 67 controls. Of 28 alleles with frequency of ≥ 10% in cases with grade ≥ 2 alanine aminotransferase (ALT) elevation [significance level = .00178 (0.05 divided by 28)], HLA-DQA1*05:05 allele carriage was found to be significantly associated with ALT elevation in 13 cases with grade ≥ 2 and 47 controls with grade 0. HLA- DQA1*05:05 was present in 30.8% of cases and in 0.0% of controls ( P=.00147; odds ratio, 45.0; 95% CI, 2.23 to 907). Suggestive associations of ALT elevation were observed with HLA-DPB1*05:01 allele carriage ( P=.00930; odds ratio, 11.5; 95% CI, 1.38 to 95.7) and HLA-A*31:01 allele carriage ( P=.01522; odds ratio, 5.86; 95% CI, 1.46 to 23.4). Conclusions: Evaluated 28 HLA alleles were not associated with development of ILD. HLA-DQA1*05:05 allele was identified as a promising marker candidate that can predict patients with a higher risk of abemaciclib-induced hepatotoxicity. Further study is necessary to confirm the association in an independent population for managing liver safety risk during abemaciclib treatment. This result also implicates an immune-mediated mechanism for abemaciclib-related hepatotoxicity. Clinical trial information: UMIN000046611.

#234 Clinical spectrum and genetic variants of Alport syndrome and thin basement membrane nephropathy—single center experience

Abstract Background and aims Alport syndrome (AS) and thin basement membrane nephropathy (TBMN) are genetically heterogeneous kidney diseases that manifest with kidney involvement, AS also with hearing and visual impairment. Electron microscopic examination shows characteristic ultrastructural changes in the glomerular basement membrane (GBM) in AS and TBMN, but cannot reliably distinguish between the two entities. Therefore, molecular genetic studies and the identification of individual pathogenic variants in the target genes are crucial to confirm the diagnosis. The aim of our study is to determine the significance of the genetic variants associated with the ultrastructural changes of GBM found in the renal biopsy. Method We retrospectively analyzed records of patients from the University Medical Centre Ljubljana in which ultrastructural GBM changes characteristic for AS and TBMN were found in the renal biopsy, including their clinical, laboratory and histological features. Molecular genetic investigations were made using the new generation sequencing method (NGS) to determine germline pathogenic variants in genes directly related to AS and TBMN (COL4A3, COL4A4 and COL4A5) and in genes that are important in syndromes with a related clinical picture (COL4A6, CD151, LMX1B, MYH9, FN1 and MYO1E). The pathogenicity of variants was determined according to the Clinical Molecular Genetic Society best practice guidelines. Results The study included 73 patients with ultrastructurally confirmed thin GBM. Indications for kidney biopsy were chronic nephritis syndrome in 33 patients (45%), acute worsening of renal function in 16 (22%), nephrotic syndrome in 9 (12%), nephrotic proteinuria and chronic kidney disease in 6 (8%), isolated proteinuria in 5 (7%) and suspected vasculitis in 4 patients (6%). At the time of kidney biopsy average age was 50 ± 16 years, average creatinine 112 ± 70 µmol/L and average estimated glomerular filtration rate (eGFR) 65 ± 24 ml/min/1.73 m2, 7 patients had eGFR below 30 ml/min/1.73 m2. Average daily proteinuria was 2.4 ± 3.3 gr and 88% of patients had hematuria. 38% of them have hearing impairment and 43% had positive familiar history of kidney disease. We recorded 33 patients (45%) with genetic variants associated with AS or TBMN: 22 patients (67%) with pathogenic variants, 2 patients (6%) with likely pathogenic and 9 patients (27%) with variants of uncertain significance. The presence of a positive genetic analysis was associated with a higher level of hematuria (p = 0.003), a lower level of proteinuria (p = 0.004) and a positive family history of kidney disease (p &amp;lt; 0.001). It was also associated with hearing loss, but the association was not statistically significant (p = 0.099). Patients with genetic variants had similar eGFR to those with negative genetics (63.9 ml/min/1.73 m2 (58.3-69.4) vs 66.2 ml/min/1.73 m2 (60.0-72.3)), p = 0.698. We also found no differences in GBM thickness in patients without compared to those with identified gene variants (213 nm (160-315) vs. 209 nm (140-410)), p = 0.761. 32 patients (44%) had only focal chronic changes and ultrastructural changes of thin GBM present on kidney biopsy and 41 patients (56%) had also been diagnosed with other renal pathology. When comparing these two groups, patients without associated pathology had lower daily proteinuria (p = 0.048), higher level of hematuria (p = 0.021), frequent hearing impairment (p = 0.008) and also positive genetics analysis (p = 0.016). Conclusion We have shown that in patients with proven ultrastructural alterations in GBM, the presence of so far recognized genetic variants associated with AS and TBMN is 45%, and corresponds to the frequency of other phenotypic characteristics of AS, including hearing impairment and positive family history. In the future, additional clinical tools will be required to accurately determine the role of coexistent thin GBM on the prognosis of patients with other relevant kidney pathology and other genetic tools beyond NGS should be employed to explore other pathologic genetic variants associated with the AS spectrum.

Exploration of the polypropylene degrading bacteria candidates from the passive zone of the Supit Urang landfill in Malang city by using the next generation sequencing (NGS) method

Exploration of the polypropylene degrading bacteria candidates from the passive zone of the Supit Urang landfill in Malang city by using the next generation sequencing (NGS) method

Validation of a next generation sequencing method for adventitious virus detection: Demonstration of sensitivity in multiple cell lines

In the past few years NGS has become the technology of choice to replace animal-based virus safety methods and this has been strengthened by the recent revision to the ICHQ5A virus safety chapter. Here we describe the validation of an NGS method using an agnostic analysis to detect and identify RNA virus and actively replicating DNA virus contaminants in cell banks. We report the results of the validation of each step in the sequencing process that established quality criteria to ensure consistent sequencing data. Furthermore, the validation of the analysis algorithm designed to identify virus specific sequences is described along with steps undertaken to ensure the integrity of the sequencing data from generation to analysis. Lastly, the validated sequencing and analysis systems were used to establish a limit of detection (LOD) for model viruses in cells that are commonly used in biomanufacturing. The LOD from these studies ranged from 1E+03 to 1E+04 genome copies and were dependent on the virus type with little variability between the different cell types. Thus, the validation of the NGS method for adventitious agent testing and the establishment of a general LOD for cell-based samples provides a suitable alternative to traditional virus detection methods.

Abstract 7024: Development of quality control methods for reliable NGS measurement of methylation in cfDNA

Abstract Background and Purpose: Reliable measurement of circulating free genomic DNA (cfDNA) methylation patterns promises a means for cancer early detection as well as treatment response. Use of Next Generation Sequencing (NGS) methods to measure the cfDNA methylome across a large number of potentially methylated CpG sites may enable earlier detection by overcoming stochastic sampling associated with the small specimens obtainable by a blood draw. Wide-spread adoption of these methods for clinical diagnostic applications will be facilitated through improved quality controls that increase reliability. The goal of this study is to assess the performance of the SNAQ-SEQ™ method as a means to establish a limit of detection (LOD) for measurement of methylation at each targeted CpG site. For this purpose, we used test materials that were developed by the National Institute for Standards and Technology (NIST) to mimic methylated cfDNA. Methods: NIST test materials were formulated by physically shearing cell line gDNA then subjecting it to size separation to mimic a size distribution similar to that observed in cfDNA, then mixing sheared DNA in its “native” state of methylation with sheared DNA that was in vitro methylated. Non-sheared NIST test materials also were assessed in these studies. Synthetic spike-in internal standards (IS) were combined with NIST test materials and the combined samples were bisulfite converted, then subjected to PCR-amplicon library preparation. Libraries were sequenced on an Illumina MiSeq instrument and bioinformatic analysis was conducted using the Qiagen CLC Workbench. Results and Conclusions: In initial testing of an off-the-shelf IS for a region of the SOX2 gene, average methylation (preserved C) across 14 targeted CpG sites was 16.4% (0.5%-50%) in the “native” NIST non-sheared sample. This was consistent with the 11.6% methylation across all of SOX2 measured by the NIST. In contrast, in IS corresponding to the targeted SOX2 region the average preserved C was 0.32% (0.03%-0.5%). Use of synthetic internal standards enabled determination of LOD for each individual methylated site, controlling for all known sources of technical error, including inefficient bisulfite conversion, nucleotide substitution error, and alignment error. Studies are now underway that use the NIST test materials to measure methylation at five targets known to be altered in cfDNA from lung cancer subjects, SOX2, CDO1, TAC1, SOX17, and HOXA7. Citation Format: James C. Willey, Erin L. Crawford, Daniel J. Craig, Thomas M. Morrison, Hua-Jun He, James G. Herman. Development of quality control methods for reliable NGS measurement of methylation in cfDNA [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7024.

Association of candidate alterations with primary resistance to KRAS G12D targeting in colorectal cancer.

170 Background: KRAS-mutant colorectal cancer (CRC) has a worse prognosis and greater resistance to therapy, attracting tremendous efforts to develop both allele-specific and pan-KRAS targeting agents including KRAS G12C and G12D inhibitors. CRC has demonstrated both primary and acquired resistance to KRAS G12C inhibitors, which can be better evaluated by circulating tumor DNA (ctDNA)-based next generation sequencing (NGS) methods without tissue sampling bias. Here, we utilized clinical ctDNA data to delineate the landscape of candidate alterations associated with primary resistance to KRAS G12D targeting in CRC. Methods: Samples from advanced CRC patients with Guardant360 data in 2021 were categorized into a KRAS G12D group and comparator groups of KRAS G12C and KRAS not detected (ND) according to KRAS mutation status. Demographics, MSI-H status, and blood tumor mutational burden (bTMB) were summarized and compared between groups using t-test for continuous variables and Fisher’s exact test for categorical variables. Co-occurrence patterns of alterations between KRAS and other genes were assessed. Primary resistance mutations were inferred by acquired resistance findings to KRAS G12C inhibitors reported by Awad et al. N Engl J Med. 2021 and Tanaka et al. Cancer Discov. 2021. Results: Among approximately 2500 samples, 16.8% had KRAS G12D, the most common KRAS mutation in CRC. The mean allele frequency of KRAS G12D (11.4%) is comparable to that of KRAS G12C (10.9%). Mean age (61.6 years), MSI-H frequency (3.8%), and mean bTMB (14.2 Mut/Mb) of KRAS G12D group is comparable to those of KRAS ND group. This contrasts with KRAS G12C with significantly lower mean age (60.2 years, p=0.01), lower MSI-H frequency (0.56%, p=0.03), and higher mean bTMB (16.3 Mut/Mb, p=0.02) compared to KRAS ND. Both KRAS G12D and G12C significantly co-occur with APC, PIK3CA, and SMAD4 alterations. FBXW7, AR, and KEAP1 alterations were unique co-occurrences to KRAS G12D, while KIT was unique to KRAS G12C. Candidate alterations associated with primary resistance in KRAS G12D CRC included simultaneously present mutations of KRAS Q61H (14.1%), G12V (6.4%), G12C (5.9%), G13D (3.6%), BRAF V600E (2.7%) and others, amplification of MET (2%), MYC (1.6%), and KRAS (1.4%), and FGFR3-TACC3 translocation (Table). Conclusions: KRAS G12D is associated with unique co-occurring molecular alterations compared to KRAS G12C in CRC. ctDNA-based NGS platforms can survey candidate alterations associated with primary resistance to KRAS G12D targeting in CRC. Further validation in preclinical models is needed. [Table: see text]

Comparison of Sinus Flora Using Various Next-Generation Sequencing Techniques Versus Standard Culturing

Background:Next generation sequencing methods are being developed to help diagnose infectious diseases at the point of care and to help resolve discrepant results. These new methods hope to replace longer, more tedious sequencing methods such as Sanger/shotgun sequencing and less sensitive culture results to provide a clinical diagnosis and start appropriate treatment sooner. In lieu of dated techniques, with next generation sequencing the physician could analyze samples in their clinic with relative ease and receive a sensitive diagnosis in a fraction of the time.&#x0D; Objective:To compare percent agreement between standard culturing results of swabbed sinus samples on blood and chocolate agar to BIOFIRE® FILMARRAY® results, and use Oxford Nanopore and 16s illumina sequencing results to resolve discrepancies.&#x0D; Study design:Swabs were taken of the nasal sinuses of 21 patients and flash frozen. Some of these swabs (15/21) were sequenced with 16s illumina sequencing. All these swabs were put into a saline solution and plated on blood and chocolate agar plates as a 1:100 loop dipped into the solution and as the original swab. These solutions were sequenced through the BIOFIRE® FILMARRAY® Torch System on a pneumonia and blood culture (BCID2) panel and through the Oxford Nanopore® MinION Mk1C® system.&#x0D; Results:The pneumonia panel had 36% agreement with blood agar and 52% agreement with chocolate agar plates. Using the top 3 genus results, either Nanopore or 16s illumina sequencing resolved 92% of discrepancies between the pneumonia panel and blood agar and 90% of discrepancies between the pneumonia panel and chocolate agar plates. The blood culture panel had 43% agreement with blood agar and 57% agreement with chocolate agar plates. Nanopore or 16s illumina sequencing resolved 92% of discrepancies between the blood panel and blood agar and 89% of discrepancies between the blood panel and chocolate agar.

Predmoter-cross-species prediction of plant promoter and enhancer regions.

Identifying cis-regulatory elements (CREs) is crucial for analyzing gene regulatory networks. Next generation sequencing methods were developed to identify CREs but represent a considerable expenditure for targeted analysis of few genomic loci. Thus, predicting the outputs of these methods would significantly cut costs and time investment. We present Predmoter, a deep neural network that predicts base-wise Assay for Transposase Accessible Chromatin using sequencing (ATAC-seq) and histone Chromatin immunoprecipitation DNA-sequencing (ChIP-seq) read coverage for plant genomes. Predmoter uses only the DNA sequence as input. We trained our final model on 21 species for 13 of which ATAC-seq data and for 17 of which ChIP-seq data was publicly available. We evaluated our models on Arabidopsis thaliana and Oryza sativa. Our best models showed accurate predictions in peak position and pattern for ATAC- and histone ChIP-seq. Annotating putatively accessible chromatin regions provides valuable input for the identification of CREs. In conjunction with other in silico data, this can significantly reduce the search space for experimentally verifiable DNA-protein interaction pairs. The source code for Predmoter is available at: https://github.com/weberlab-hhu/Predmoter. Predmoter takes a fasta file as input and outputs h5, and optionally bigWig and bedGraph files.

Chapter 2 - Approaches to diagnosis for individuals with a suspected inherited white matter disorder

Leukodystrophies are heritable disorders with white matter abnormalities observed on central nervous system magnetic resonance imaging. Pediatric leukodystrophies have long been known for their classically high, "unsolved" rate. Indeed, these disorders provide a diagnostic dilemma for many clinicians as over 100 genetic disorders alone may present with white matter abnormalities, with this figure not taking into account the substantial number of infectious agents, toxicities, and acquired disorders that may affect the white matter of the brain. Achieving a diagnosis may be the single most important step in the clinical course of a leukodystrophy-affected individual, with important implications for care and quality of life. For certain disorders, prompt recognition can direct therapeutic intervention with significant implications and requires urgent recognition. In this review, we cover newborn screening efforts, standard-of-care testing methodologies, and next generation sequencing approaches that continue to change the landscape of leukodystrophy diagnosis. Early studies have shown that next generation sequencing approaches, particularly exome and now genome sequencing have proven to be powerful in helping resolve many cases that were refractory to a single gene or linkage analysis approach. In addition, other methods are required for cases that remain persistently unsolved after next generation sequencing methods have been used. In the past more than half of affected individuals never achieved an etiologic diagnosis, and when they did, the reported times to diagnosis were >5 years although molecular testing has allowed this to be reduced to closer to 16 months. For affected families, next generation sequencing technologies have finally provided a way to fill gaps in diagnosis.

Bacteria Analysis in the Ciwalen River Garut using Next Generation Sequencing of 16S Ribosomal RNA

&#x0D; &#x0D; &#x0D; The Ciwalen River flows through Garut city, West Java, Indonesia. This river is bordered by hundreds of leather tanning enterprises and community toilet waste. The purpose of this research is to analyse bacteria in Ciwalen river water using the Next Generation Sequencing (NGS) method for the 16s ribosomal RNA gene using V1-V9 primer pairs, which will amplify the entire length of the rRNA gene and allow for species identification. The data revealed that there were 104,000 reads, 150,232,539 bases, and 81,761 bacterial species. Proteiniclasticum ruminis, Fusibacter ferrireducens, Fusibacter fontis, Fusibacter tunisiensis, Paludibacter propionicigenes, Arcobacter cloacae, Alishewanella jeotgali, Thiovirga sulfuroxydans, Pseudomonas fluvialis, and Thauera mechernichensis are the main bacterial species. In this study, another bacteria, Klebsiella pneumoniae, was also found which is known to degrade heavy metals, chromium, timbal &amp; cadmium (Cr, Pb and Cd). The profile of bacteria, as well as the presentation of their existence in this water sample, demonstrates the appropriateness of heavy metals from leather tannery waste in the Ciwalen river.&#x0D; &#x0D; &#x0D;

Exploration The Candidates of Xenobiotic Degrading Indigenous Bacteria from Probolinggo City Landfill by Using Next Generation Sequencing (NGS)

Soil bacteria from tropical environments play a significant role in resolving various environmental issues, including biodegradation. Exploratory research on biodiversity is crucial to develop and harness the potential of different types of soil bacteria that are highly abundant. The bacterial diversity in landfills is typically high due to the decomposition of organic and inorganic waste, creating a favorable medium for the growth and development of soil bacteria. This study aims to assess the candidates of xenobiotic degrading indigenous bacteria from the Probolinggo City landfill using Next Generation Sequencing (NGS) method. The research stages include: 1) sampling, 2) isolation of genomic DNA from samples using the ZymoBIOMICS DNA MiniPrep Kit from Zymo Research, 3) amplification of isolated DNA with primers 16S 27F – 1429R, 4) sequencing the results of DNA amplification with NGS, 5) downstream analysis of the results using software Pavian Krona Tools, and 6) narrative analysis review to identify the candidates of xenobiotic degrading indigenous bacteria. The results show that soil samples from the Probolinggo City landfill exhibited a high diversity of bacterial communities. Based on NGS analysis, 2400 bacterial species were identified, comprising 56 genera, 17 orders, 4 classes, and 4 phyla, with respective abundances of Proteobacteria (70%), Firmicutes (15%), Planctomycetes (2%), and Cyanobacteria (0,3%). Based on the narrative analysis review, several bacteria in the Probolinggo City landfill exhibited potential as: 1) polypropylene-degrading bacteria, including Bacillus cereus, B. licheniformis and B. thuringiensis. 2) styrofoam degrading bacteria, namely Bacillus amyloliquefaciens, Bacillus cereus, Bacillus firmus and Pseudomonas aeruginosa. 3) total ammonia nitrogen (TAN) reducing bacteria, including Bacillus megaterium. 4) pesticide degrading bacteria Profenofos and Chlorantraniliprole, including Bacillus stearothermophilus. and 5) tannic acid degrading bacteria, including Pantoea dispersa. These results indicate that the Probolinggo City landfill is a good habitat for various xenobiotic-degrading bacteria, then the isolation of specific bacteria can be designed using an appropriate selective medium.

Efficient extraction of adventitious virus nucleic acid using commercially available methods

An essential step in pharmaceutical product development is screening for contamination with adventitious agents, and there is desire to develop highly sensitive assays to detect adventitious viral nucleic acid. This study sought to examine the nucleic acid extraction efficiency of three viral candidates in relevant background matrices using four different extraction methods. Three model adventitious viruses, Minute virus of Mice, Porcine Circovirus, and Feline Leukemia Virus, were diluted within a variety of background matrices relevant to pharmaceutical production methods. Upon extraction, the nucleic acid was quantified using droplet digital PCR methods. Four nucleic acid extraction methods were assessed, including commercially available kits and manual extraction methods. Each method recovered nucleic acid post-extraction for each of the model viruses within the tested background matrices. The silica-column based method recovered a greater amount of viral nucleic acid, compared to the other methods tested. Similar trends were observed when model virus was diluted in bioreactor supernatant, which replicates industry testing conditions and provides details on which extraction methods might be used in Next Generation Sequencing and PCR methods for detecting contamination within pharmaceutical products.