Genome Analysis Toolkit Research Articles

Diversity and structure assessment of the genetic resources in a germplasm collection from a vanilla breeding programme in Madagascar

AbstractA breeding programme of aromatic vanilla, dating back to 1944, was conducted in Ambohitsara, Antalaha, SAVA (Sambava, Antalaha, Vohemara, Andapa) – Madagascar. Imported, local, wild and cultivated vanillas were used as progenitors and thousands of hybrids were generated. However, this germplasm has not undergone any genetic evaluation, and it appears that these valuable genetic resources have been dispersed or lost after the end of the programme (2000). This study aims to investigate the genetic diversity and structure of rescued genotypes currently held in a local collection in Antalaha. Double digest restriction associated-site (RAD)-seq (ddRAD)-seq protocol was applied, providing 865 million read sequences from 56 accessions. The ddRAD sequences have been deposited to the SRA archive of NCBI. From the data, 23,701 filtered concordant common Single Nucleotide Polymorphisms (SNPs) were identified using the three widely used tools (Stacks, BCFtools, Genome Analysis ToolKit - GATK) for short-read library sequencing. These SNPs were used for germplasm evaluation. Clustering analysis segregated samples into five genetic groups: Vanilla planifolia, Vanilla pompona, hybrid Tsitaitra, Vanille Banane and the phenotype Tsivaky. Our analysis revealed distinct subgroups within V. pompona and Tsitaitra, emphasizing the importance of further characterization to accurately reflect the genetic diversity and facilitate better utilization of these accessions in future research and germplasm management. The presence of private alleles in all groups (from 487 to 2866) indicated that populations were diverging and represented a large gene pool that could be useful for future breeding efforts. The genetic data obtained from this study offers valuable insights into the genetic diversity and structure of the vanilla population, with potential applications in breeding and conservation efforts.

Transforming genetic data for a convolutional neural network using genotype posterior probability: Algorithm for handling incorrectly imputed multiallelic variants for multiple genetic datasets

AbstractBackgroundAlzheimer’s disease (AD) genetic research utilizing genome‐wide association study data often requires imputation. Genotypes are imputed probabilistically by the Hidden Markov Model and converted into one‐dimensional categorical variables for a convolutional neural network (CNN). Such a conversion, however, contains uncertainty, which can mislead CNN in determining AD‐risk factors when added up. Also, the imputed genotypes are quality‐controlled (QCed) by using PLINK, a widely used whole genome data analysis toolset. However, the QC process of PLINK cannot exclude all incorrectly imputed multiallelic genetic variants (IMGs). To address such issues, we proposed a post‐quality control algorithm to transform the genetic dataset into three‐dimensional one‐hot encoding weighted by genotype posterior probabilities.MethodWe collected 1876, 173, and 384 participants from the Alzheimer’s Disease Neuroimaging Initiative, Imaging and Genetic Biomarkers for AD, and Longitudinal Early‐Onset Alzheimer’s Disease Study, respectively. Genotypes were imputed through Markov Chain Haplotyping and QCed using PLINK (Fig. 1). Then the data was transformed into 5×2xN three‐dimensional one‐hot encoding; 5 indicates the number of nucleotides (4) including insertion (1), 2 indicates genotype copy, and N indicates the number of all available markers. One‐hot encoding data was weighted by genotype posterior probabilities obtained by Genome Analysis Toolkit. The weighting algorithm also re‐imputes IMGs based on their genotype posterior probabilities (Fig. 2).ResultAll genotypes were successfully transformed into one‐hot encodings composed of genotype posterior probabilities. Each participant had about 6,980 IMGs with a standard deviation of 822 (Fig. 3). The percentage of IMGs for each chromosome was about 0.274% with a standard deviation of 0.234 (Table 1). All IMGs were corrected based on genotype posterior probabilities and transformed into one‐hot encodings (Fig. 4).ConclusionThe QC process is essential for minimizing possible bias and errors that would be imposed on computational models. Transforming genetic data into one‐hot encodings weighted by genotype posterior probability can present genotypes with their imputation quality. Furthermore, it can fully utilize CNN’s capacity by allowing it to determine various features.

Nested and Large Nested Subtypes of Urothelial Carcinoma of the Upper Urinary Tract: A Multi-institutional Study

Nested urothelial carcinoma (NUC) and large nested urothelial carcinoma (LNUC) of the upper urinary tract are exceedingly rare. This has contributed to the paucity of information regarding their clinicopathological and molecular characteristics. To address this knowledge gap, we explored the largest cohort to date of these rare tumors, comprising resection specimens of 10 LNUC and 7 NUC, from 7 participating institutions. Clinicopathological data were retrieved and documented. Whole exome sequencing and RNA sequencing were performed on the Illumina NovaSeq 6000 sequencer. The data generated were analyzed using the genome analysis toolkit pipeline. Somatic mutations were annotated using funcotator tool to identify pathogenic/likely pathogenic variants. Tumor mutational burden was calculated using python-based “pyTMB” tool. Microsatellite instability analysis was done using MSIsensor2 and the Idylla platform. Differential expression analysis of genes in LNUC and NUC along with mRNA expression–based molecular subtyping was performed by analyzing expression pattern of markers used in The Cancer Genome Atlas subclassification of bladder carcinoma. Both tumor types were more common in older males, were unifocal, and occurred more commonly mixed with minor components of predominantly conventional urothelial carcinoma. Overlying low-grade papillary urothelial carcinoma was significantly more common in LNUC (P = .034). On follow-up (LNUC: median, 10 months; range, 3-84 months; NUC: median, 9 months; range, 2-48 months), LNUC had better clinical outcomes (P = .031). Pathogenic mutations in FGFR3 and PIK3CA were significantly more common in LNUC (P = .049 and P = .044, respectively), with the latter present exclusively in LNUC. Seventy-five percent of the cases showed tumor mutational burden of <10, and all cases were microsatellite-stable. FGFR3 mutations were also more common in low-stage tumors. This study expands on the clinicopathological spectrum of NUC and LNUC of the upper urinary tract and is the first to comprehensively analyze the molecular profile of these tumors, highlighting pathogenic genetic alterations of potential therapeutic and prognostic value.

Integrated variant allele frequency analysis pipeline and R package: easyVAF.

Somatic sequence variants are associated with cancer diagnosis, prognostic stratification, and treatment response. Variant allele frequency (VAF), the percentage of sequence reads with a specific DNA variant over the read depth at that locus, has been used as a metric to quantify mutation rates in these applications. VAF has the potential for feature detection by reflecting changes in tumor clonal composition across treatments or time points. Although there are several packages, including Genome Analysis Toolkit and VarScan, designed for variant calling and rare mutation identification, there is no readily available package for comparing VAFs among and between groups to identify loci of interest. To this end, we have developed the R package easyVAF, which includes parametric and nonparametric tests to compare VAFs among multiple groups. It is accompanied by an interactive R Shiny app. With easyVAF, the investigator has the option between three statistical tests to maximize power while maintaining an acceptable type I error rate. This paper presents our proposed pipeline for VAF analysis, from quality checking to group comparison. We evaluate our method in a wide range of simulated scenarios and show that choosing the appropriate test to limit the type I error rate is critical. For situations where data is sparse, we recommend comparing VAFs with the beta-binomial likelihood ratio test over Fisher's exact test and Pearson's χ2 test.

GATK-gCNV enables the discovery of rare copy number variants from exome sequencing data.

Copy number variants (CNVs) are major contributors to genetic diversity and disease. While standardized methods, such as the genome analysis toolkit (GATK), exist for detecting short variants, technical challenges have confounded uniform large-scale CNV analyses from whole-exome sequencing (WES) data. Given the profound impact of rare and de novo coding CNVs on genome organization and human disease, we developed GATK-gCNV, a flexible algorithm to discover rare CNVs from sequencing read-depth information, complete with open-source distribution via GATK. We benchmarked GATK-gCNV in 7,962 exomes from individuals in quartet families with matched genome sequencing and microarray data, finding up to 95% recall of rare coding CNVs at a resolution of more than two exons. We used GATK-gCNV to generate a reference catalog of rare coding CNVs in WES data from 197,306 individuals in the UK Biobank, and observed strong correlations between per-gene CNV rates and measures of mutational constraint, as well as rare CNV associations with multiple traits. In summary, GATK-gCNV is a tunable approach for sensitive and specific CNV discovery in WES data, with broad applications.

Whole Animal Genome Sequencing: user-friendly, rapid, containerized pipelines for processing, variant discovery, and annotation of short-read whole genome sequencing data.

Advancements in massively parallel short-read sequencing technologies and the associated decreasing costs have led to large and diverse variant discovery efforts across species. However, processing high-throughput short-read sequencing data can be challenging with potential pitfalls and bioinformatics bottlenecks in generating reproducible results. Although a number of pipelines exist that address these challenges, these are often geared toward human or traditional model organism species and can be difficult to configure across institutions. Whole Animal Genome Sequencing (WAGS) is an open-source set of user-friendly, containerized pipelines designed to simplify the process of identifying germline short (SNP and indel) and structural variants (SVs) geared toward the veterinary community but adaptable to any species with a suitable reference genome. We present a description of the pipelines [adapted from the best practices of the Genome Analysis Toolkit (GATK)], along with benchmarking data from both the preprocessing and joint genotyping steps, consistent with a typical user workflow.

Identification of pathogenic variants in the Brazilian cohort with Familial hypercholesterolemia using exon-targeted gene sequencing

Familial hypercholesterolemia (FH) is a monogenic disease characterized by high plasma low-density lipoprotein cholesterol (LDL-c) levels and increased risk of premature atherosclerotic cardiovascular disease. Mutations in FH‐related genes account for 40% of FH cases worldwide. In this study, we aimed to assess the pathogenic variants in FH-related genes in the Brazilian FH cohort FHBGEP using exon-targeted gene sequencing (ETGS) strategy. FH patients (n = 210) were enrolled at five clinical sites and peripheral blood samples were obtained for laboratory testing and genomic DNA extraction. ETGS was performed using MiSeq platform (Illumina). To identify deleterious variants in LDLR, APOB, PCSK9, and LDLRAP1, the long-reads were subjected to Burrows-Wheeler Aligner (BWA) for alignment and mapping, followed by variant calling using Genome Analysis Toolkit (GATK) and ANNOVAR for variant annotation. The variants were further filtered using in-house custom scripts and classified according to the American College Medical Genetics and Genomics (ACMG) guidelines. A total of 174 variants were identified including 85 missense, 3 stop-gain, 9 splice-site, 6 InDel, and 71 in regulatory regions (3′UTR and 5′UTR). Fifty-two patients (24.7%) had 30 known pathogenic or likely pathogenic variants in FH-related genes according to the American College Medical and Genetics and Genomics guidelines. Fifty-three known variants were classified as benign, or likely benign and 87 known variants have shown uncertain significance. Four novel variants were discovered and classified as such due to their absence in existing databases. In conclusion, ETGS and in silico prediction studies are useful tools for screening deleterious variants and identification of novel variants in FH-related genes, they also contribute to the molecular diagnosis in the FHBGEP cohort.

Genomic profiles of Indonesian colorectal cancer patients.

Background: Colorectal cancer (CRC) is one of the most commonly diagnosed cancers worldwide and genetic mutation plays a vital role in CRC development. A previous study has suggested that genetic alterations among Indonesian patients with CRC might differ from those known in developed countries. This study aimed to describe the genomic profiles of Indonesian patients with CRC. Methods: A total of 13 patients were recruited for this study from May to July 2019. Tissue samples were collected, and genomic DNA was extracted from the samples. AmpliSeq for Illumina Cancer HotSpot Panel v2 Next-generation sequencing was used for DNA sequencing and a genome analysis toolkit was used for local realignment around the discovered variants. Results: A total of 45 genes comprising 391 single nucleotide variants (SNVs) with a depth >10 were observed. The genes with the most variants were STK11, SMAD4, EGFR, and ERBB4 and the genes with the most non-synonymous variants were SMAD4, TP53, FGFR3, CDKN2A, and STK11. Genes and SNVs in at least 90% of all samples consisted of 43 genes comprising 286 variants. Genes with the most non-synonymous SNVs were EGFR, SMO, FGFR3, TP53, STK11, CDKN2A. Genes related to the chromosomal instability pathway, such as TP53, SMAD4, KRAS, and APC, are also found in the analysis. Conclusions: Our findings showed that all patients with CRC in this study had genetic mutations in the chromosomal instability pathway. Analysis of genetic mutation of Indonesian patients with CRC might be crucial for advanced targeted therapy and for better clinical outcomes.

Genomic analysis from BLASST-1 (Bladder Cancer Signal Seeking Trial) of nivolumab, gemcitabine, and cisplatin in patients with MIBC undergoing cystectomy.

559 Background: BLASST-1 is multi-center phase II trial evaluating neoadjuvant nivolumab (N) with gemcitabine-cisplatin (GC) for patients (pts) with MIBC undergoing radical cystectomy (RC) (NCT03294304). 41 pts with MIBC (cT2-T4a, N≤1, M0) were enrolled between Feb 2018 and June 2019; (cT2N0 90%, cT3N0 7%, cT4N1 3%). Pts received C (70mg/m2) IV on D1, G (1000mg/m2) on D1, D8 and N (360 mg) IV on D8 every 21 days for 4 cycles followed by RC within 8 wks. Primary endpoint was pathologic down staging (PaR; ≤pT1N0). Safety, Relapse-free survival (RFS), Progression-free survival (PFS) and biomarker analyses were secondary endpoints. PaR rate was 65.8%, pCR (≤pT is N0) rate was 49% and there were no safety concerns or delays to RC. At a median follow-up of 15.8 mos, 12-month RFS rate was 85.4% and PFS including death from any cause was 83%. We now report correlation of PaR with tumor mutation patterns of responders (R) and non-responders (NR) using Whole Genome Sequencing (WGS). Methods: DNA was extracted from pre-treatment tumor samples and sequenced to an average depth of 150X and DNA extracted from matched normal tissue (peripheral blood) to a mean depth of 50X. We analyzed 32 Tumor/Normal pairs and 6 Tumor only Whole Genome Samples; 26 pts were classified as (R) and 12 as (NR). Raw sequencing data samples were aligned to hg38 genome build using Burrows-Wheeler Aligner (BWA) followed by duplicate-read removal and base-quality score recalibration using the Genome Analysis Toolkit (GATK). Somatic SNV and INDELS were called by combination of 5 callers (Mutect2, Strelka, VarScan, Platypus and SomaticSniper) for Tumor/Normal pairs and Mutect2 for Tumor only samples following the guidelines of GDC DNA-Seq analysis pipeline. Set of genes known to be significantly mutated in MIBC and shown to impact response/resistance to chemotherapy/immunotherapy respectively were selected. Samples were grouped by response status. Results: Median tumor mutational burden (TMB) for the dataset closely matches with TCGA results. Genes ERCC2, ARID1A, DSP, HMCN1, ERBB2, ERBB3, STAG2, BRCA2 present in (R) only, whereas VHL, ERCC4, PALB2, CDKN2A and CSMD3 present in (NR) only. We also grouped genes based on their biological processes by known Oncogenic Signaling Pathways and the 3 most common pathways are Genome Integrity, RTK Signaling and Transcription Factor with the latter two primarily enriched in (R). We identified a SNP rs2853669 in 5 (NR) and 14 (R). Conclusions: The genomic analysis suggests ERCC2, ARID1A, DSP, HMCN1, ERBB2, ERBB3,STAG2, BRCA2 correlated with PaR and VHL, ERCC4, PALB2, CDKN2A and CSMD3 correlated with lack of response. In addition, RTK Signaling and Transcription Factor were primarily enriched in (R). This genomic correlation of response/resistance to neoadjuvant chemo-immunotherapy in MIBC can help guide future biomarker-driven studies. Clinical trial information: NCT03294304 .

Abstract A011: Whole genome sequencing of the Alabama Hereditary Cancer Cohort to identify African American breast cancer genetic risk variants

Abstract Regardless of having higher rates of triple-negative breast cancer (TNBC) and breast cancer-related deaths, African Americans are drastically understudied in hereditary breast cancer research. Our group has established the Alabama Hereditary Cancer Cohort to carry out next-generation sequencing (NGS) to address this gap. These efforts aim to identify inherited breast cancer risk variants in African Americans. Interestingly, African American TNBC tumors have been investigated through NGS, identifying somatic mutations unique to African American breast cancer. Now, African American-specific variants associated with inherited risk need to be identified, including those in genes harboring somatic mutations in African American TNBC. This study carried out whole genome sequencing (WGS) to investigate inherited African American breast cancer risk. All coding and non-coding regions of the nuclear genome and the entirety of the mitochondrial genome were explored, all of which can play a role in hereditary breast cancer risk. Individuals provided a blood or saliva sample for DNA extraction upon study consent. Subsequently, paired-end Illumina sequencing was carried out. Fastq files were trimmed using Trimmomatic and further processed according to the Genome Analysis ToolKit Best Practices, resulting in variant call format (VCF) files. Coding, non-coding, and mitochondrial regions were individually extracted using VCFtools and UCSC Table Browser tracks. Coding and mitochondrial variants were annotated using Annovar and MSeqDR, respectively. Coding variants were further filtered for minor allele frequency (MAF) classes (i.e., rare and low-frequency) and mutation type (i.e., protein-truncating variants; PTVs) using R (v. 4.2). Preliminary WGS data of 60 African American hereditary breast cancer cases have identified statistically significant rare and low-frequency PTVs in genes reported to harbor somatic mutations exclusively in African American TNBC tumors. Furthermore, we have identified variants in prostate cancer susceptibility genes that are statistically associated with African American breast cancer risk. We have also identified multiple variants in the mitochondrial genome that are statistically linked to breast cancer risk, some African American-specific. Our data shows that WGS is an invaluable tool for identifying breast cancer susceptibility variants. Further sequencing and functional analyses will validate our preliminary findings. Citation Format: Troy LoBue, Isaac Mcneely, Nancy Merner. Whole genome sequencing of the Alabama Hereditary Cancer Cohort to identify African American breast cancer genetic risk variants [abstract]. In: Proceedings of the 15th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2022 Sep 16-19; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr A011.

Screening of Candidate Genes Associated with Brown Stripe Resistance in Sugarcane via BSR-seq Analysis.

Sugarcane brown stripe (SBS), caused by the fungal pathogen Helminthosporium stenospilum, is one of the most serious threats to sugarcane production. However, its outbreaks and epidemics require suitable climatic conditions, resulting in the inefficient improvement of the SBS resistance by phenotype selection. The sugarcane F1 population of SBS-resistant YT93-159 × SBS-susceptible ROC22 was used for constructing the bulks. Bulked segregant RNA-seq (BSR-seq) was then performed on the parents YT93-159 (T01) and ROC22 (T02), and the opposite bulks of 30 SBS-susceptible individuals mixed bulk (T03) and 30 SBS-resistant individuals mixed bulk (T04) collected from 287 F1 individuals. A total of 170.00 Gb of clean data containing 297,921 SNPs and 70,426 genes were obtained. Differentially expressed genes (DEGs) analysis suggested that 7787 and 5911 DEGs were identified in the parents (T01 vs. T02) and two mixed bulks (T03 vs. T04), respectively. In addition, 25,363 high-quality and credible SNPs were obtained using the genome analysis toolkit GATK for SNP calling. Subsequently, six candidate regions with a total length of 8.72 Mb, which were located in the chromosomes 4B and 7C of sugarcane wild species Saccharum spontaneum, were identified, and 279 genes associated with SBS-resistance were annotated by ED algorithm and ΔSNP-index. Furthermore, the expression profiles of candidate genes were verified by quantitative real-time PCR (qRT-PCR) analysis, and the results showed that eight genes (LRR-RLK, DHAR1, WRKY7, RLK1, BLH4, AK3, CRK34, and NDA2) and seven genes (WRKY31, CIPK2, CKA1, CDPK6, PFK4, CBL2, and PR2) of the 20 tested genes were significantly up-regulated in YT93-159 and ROC22, respectively. Finally, a potential molecular mechanism of sugarcane response to H. stenospilum infection is illustrate that the activations of ROS signaling, MAPK cascade signaling, Ca2+ signaling, ABA signaling, and the ASA-GSH cycle jointly promote the SBS resistance in sugarcane. This study provides abundant gene resources for the SBS resistance breeding in sugarcane.

Myosin Mutations and Sudden Sensorineural Hearing Loss: Results of Whole Exome Sequencing.

Idiopathic sudden sensorineural hearing loss (ISSNHL) affects 66,000 patients per year in the United States. Genetic mutations have been associated with progressive hearing loss; however, genetic mutations associated with ISSNHL have not been identified. A prospective cohort study of adults older than 18 years presenting with ISSNHL at a tertiary academic medical center. Whole exome sequencing (WES) was conducted using Genome Analysis Toolkit best practices. An automated diagnostic screen employing a variety of models for pathogenicity was conducted across all genes with no specific targets. Candidate pathogenic variants were reviewed by a team of geneticists and clinicians. Variants were crossed-referenced with 92 known hearing loss associated genes. Twenty-nine patients with SSNHL were screened using WES. The average age of patients was 53 ± 17.1 years, and most patients were White (62%) and men (55%). The mean pure tone average was 64.8 ± 31.3 dB for the affected ear. Using a 0.1% allele frequency screen, 12 (41%) cases had a mutation in any of the nine selected myosin genes. When we restrict to singletons (allele frequency = 0%), 21% (n = 6) of cases have qualifying variants, whereas only 3.8% (n = 481) of 12,577 healthy controls carry qualifying variants (p < 0.01). Most mutations (80%) were missense mutations. Of the novel mutations, one was a frameshift mutation, and two were a stop-gained function. Three were missense mutations. Myosin mutations may be associated with ISSNHL. However, larger population screening is needed to confirm the association of myosin mutation with ISSNHL and steroid responsiveness.

Susceptibility study on the germline rare variants of bromodomain and extraterminal domain protein family-encoding genes and patients with cancer living in some regions of China

Objective: To explore the relationship between germline rare variants of bromodomain and extraterminal domain (BET) protein family-encoding genes and susceptibility to cancer in some regions of China. Methods: Capturing probes were designed for bromodomain-containing protein 2 (BRD2), BRD3 and BRD4 genes, and Illumina high-throughput sequencing platform was used to conduct targeted sequencing of genomic DNA of peripheral blood leukocytes from 1 673 patients with cancer and 1 661 individuals without cancer recruited between October 2015 and July 2018 from Chinese PLA General Hospital, the Second Affiliated Hospital of Guangxi Medical University, People's Hospital of Macheng City, Hubei Province and Geneplus-Beijing Co. Ltd. Mutation detection and analysis were carried out according to the genome analysis toolkit (GATK) best practice guidelines, ANNOVAR and VEP software were used for annotation, and germline rare variants in BET family were screened. To determine potential pathogenic germline rare variants, clinical and experimental evidence was obtained from the ClinVar database and SIFT and Polyphen-2 softwares were used to predict pathogenicity. Fisher's exact test was used to compare the difference of the carrying rate of variants in the case group and the control group, and multivariate regression analysis was performed with the SKAT software with sex and age used as covariates. Results: Among the 1 673 cancer patients, 911 were males and 762 were females, with the mean age was (57.9±11.7) years. There were 1, 111 cases (66.4%) of lung cancer, 266 cases (15.9%) of colorectal cancer, 186 cases of breast cancer (11.1%), and 110 cases (6.6%) of esophagus or gastric cancer. In the same period 1, 661 non-tumor control individuals were recruited, including 821 males and 840 females, with the mean age was (44.5±13.9) years. It was observed that there were 4 potential pathogenic germline rare variants in BRD2 gene carried by 17 patients with cancer, 5 potential pathogenic germline rare variants in BRD3 gene and 8 potential pathogenic germline rare variants in BRD4 gene. The carrying rate of potential pathogenic germline rare variants in BRD2 gene in cancer patients was 1.02% (17/1 673), significantly higher than that in controls without cancer [0 (0/1 661); OR=+∞, 95%CI: 4.81-+∞, P<0.001]. The carrying rate of potential pathogenic germline rare variants in BRD3 gene in cancer patients was 0.24% (4/1 673), and the difference was not statistically significant compared with controls without cancer [0.12% (2/1 661); OR=1.99, 95%CI: 0.46-10.47, P=0.690]. The carrying rate of potential pathogenic germline rare variants in BRD4 gene in cancer patients was 0.18% (3/1 673), and the difference was not statistically significant compared with controls without cancer [0.36% (6/1 661); OR=0.50, 95%CI: 0.14-2.08, P=0.340]. Furthermore, the dataset of whole exome sequencing of Chinese individuals in "Huabiao Project" was used as an additional control, and the rate of carrying BRD2 rare variants in cancer patients was 17/3 346 (0.51%), significantly higher than that in controls without cancer [0.07% (3/4 154); OR=7.07, 95%CI: 2.32-22.83, P<0.001]. Among the 17 patients carrying 4 potentially pathogenic germline rare variants of BRD2 gene, 9 were patients with lung cancer, 6 were patients with colorectal cancer, 1 was patient with breast cancer, and 1 was patients with esophagus or gastric cancer. The carrying rate of potential pathogenic germline rare variants in BRD2 gene in lung cancer patients was 0.81 (9/1 111), significantly higher than that in controls without cancer [0(0/1 661); OR=+∞, 95%CI: 3.95-+∞,P<0.001]. The carrying rate of potential pathogenic germline rare variants in BRD2 gene in patients with colorectal cancer was 2.26% (6/266), significantly higher than that in controls without cancer [0(0/1 661); OR=+∞, 95%CI: 9.03-+∞, P<0.001]. Wilcoxon rank-sum test results showed that patients with colorectal cancer carrying BRD2 rare variants had an earlier age at diagnosis [(47.0±7.4) vs (57.2±12.1) years old, P=0.017]. Conclusions: BRD2 gene may be served as a candidate genetic susceptibility gene for lung cancer and colorectal cancer. Carrying BRD2 potential pathogenic germline rare variants is associated with higher risk of lung cancer and colorectal cancer, and with earlier age of colorectal cancer.

CAPG: comprehensive allopolyploid genotyper.

Genotyping by sequencing is a powerful tool for investigating genetic variation in plants, but many economically important plants are allopolyploids, where homoeologous similarity obscures the subgenomic origin of reads and confounds allelic and homoeologous SNPs. Recent polyploid genotyping methods use allelic frequencies, rate of heterozygosity, parental cross or other information to resolve read assignment, but good subgenomic references offer the most direct information. The typical strategy aligns reads to the joint reference, performs diploid genotyping within each subgenome, and filters the results, but persistent read misassignment results in an excess of false heterozygous calls. We introduce the Comprehensive Allopolyploid Genotyper (CAPG), which formulates an explicit likelihood to weight read alignments against both subgenomic references and genotype individual allopolyploids from whole-genome resequencing data. We demonstrate CAPG in allotetraploids, where it performs better than Genome Analysis Toolkit's HaplotypeCaller applied to reads aligned to the combined subgenomic references. Code and tutorials are available at https://github.com/Kkulkarni1/CAPG.git. Supplementary data are available at Bioinformatics online.

Evaluation of Breast Implant-Associated Anaplastic Large Cell Lymphoma With Whole Exome and Genome Sequencing.

Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is a rare malignancy originating from the periprosthetic capsule of a textured, most often macrotextured, breast implant. Identified in women whose indications for breast implants can be either aesthetic or reconstructive, the genomic underpinnings of this disease are only beginning to be elucidated. The aim of this study was to evaluate the exomes, and in some cases the entire genome, of patients with BIA-ALCL. Specific attention was paid to copy number alterations, chromosomal translocations, and other genomic abnormalities overrepresented in patients with BIA-ALCL. Whole-exome sequencing was performed on 6 patients, and whole-genome sequencing on 3 patients, with the Illumina NovaSeq 6000 sequencer. Data were analyzed with the Illumina DRAGEN Bio-IT Platform and the ChromoSeq pipeline. The Pathseq Genome Analysis Toolkit pipeline was used to detect the presence of microbial genomes in the sequenced samples. Two cases with STAT3 mutations and 2 cases with NRAS mutations were noted. A critically deleted 7-Mb region was identified at the 11q22.3 region of chromosome 11, and multiple nonrecurrent chromosomal rearrangements were identified by whole-genome sequencing. Recurrent gene-level rearrangements, however, were not identified. None of the samples showed evidence of potential microbial pathogens. Although no recurrent mutations were identified, this study identified mutations in genes not previously reported with BIA-ALCL or other forms of ALCL. Furthermore, not previously reported with BIA-ALCL, 11q22.3 deletions were consistent across whole-genome sequencing cases and present in some exomes.

Clinical Utility of Next-Generation Sequencing Panel Testing in the Evaluation of Arteriovenous Malformations

Abstract Arteriovenous malformations (AVMs) are vascular lesions in which an overgrowth of blood vessels of varying sizes develops with one or more direct connections between the arterial and venous circulation. AVMs are seen in sporadic and syndromic conditions that are caused by a variety of genomic alterations. Here, we performed a retrospective review of the cases sent for next-generation sequencing (NGS) analysis for diseases of somatic mosaicism (DoSM). Specimens from 54 patients with clinical indication of AVMs were submitted for the DoSM NGS panel between October 2013 and Dec 2021. DNA extraction and sequence analysis were performed on affected tissues, including fresh tissue, formalin-fixed paraffin-embedded tissue, fibroblast cultures, and buccal specimens. Single-nucleotide variants (SNVs) with variant allele fractions (VAFs) greater than 3% and small insertions and deletions (indels, &amp;lt;21 bp) were called using VarScan2, Genome Analysis Toolkit (GATK), and Pindel. Variants with VAFs between 1-3% were manually reviewed based on the sequencing data quality and the known clinical significance. 38/54 (69.1%) patients were females and 16/54 (30.9%) were males. Ages ranged from 1 month to 73 years (median age 17 years). Most of the patients were indicated with sporadic AVM (81%), although additional clinical indications were noticed, including unspecified congenital vascular malformation (9.1%), capillary malformation (5.5%), arteriovenous fistula, and AVM associated with capillary and lymphatic malformations (1.8% each). The biopsied lesion was most often located in the head (43.6%), followed by the limbs (30.9%), and unspecified areas of the body in the remaining 25.5%. Among the 54 cases, 37 (68.5%) cases had pathogenic and/or likely pathogenic (P/LP) variants identified, 2 cases (3.7%) had variants of unknown significance, and the remaining 15 cases (27.8%) had negative results. MAP2K1 variants were found in 12 samples, followed by KRAS (8), TEK (7), PTEN (5), BRAF (4), TSC2 (2), HRAS (2), RASA1 (2), and PDGFRB (1). Of note, four cases had two P/LP variants. Among the 37 positive cases, 32 cases had somatic alterations; the remaining 5 cases had at least one germline P/LP variant, including PTEN (4) and RASA1 (1). In summary, the diagnostic yield of cases with clinical indication of AVMs was 68.5% using our in-house DoSM NGS panel. This study demonstrates the clinical utility of the DoSM NGS panel testing in the evaluation of a cohort with clinical presentations of AVMs.

Abstract 15595: Whole Genome Sequencing to Identify Predictors of IVIG Response in Kawasaki Disease

Introduction: Kawasaki Disease (KD) leads as a cause of acquired cardiovascular disease among children in developed countries. Around~20% of patients are refractory to high-dose intravenous immunoglobulin (IVIG), the standard treatment, and are at high risk of developing coronary artery aneurysms. Hypothesis: Whole genome sequencing (WGS) will identify specific predictors of non-response and inform the mechanism of IVIG action. Methods: KD patients were diagnosed by the American Heart Association and the American Academy of Pediatrics (AHA/AAP) criteria and treated by AHA guidelines. IVIG refractoriness was defined by persistent or recurrent fever (&gt;38C)&gt;36 hours after completing infusion. We performed a case-control study with WGS on DNA from saliva or blood from 107 responders versus 103 non-responders. After processing informatics using the pipeline of Genome Analysis Toolkit (GATK), additive genetic models were assessed for all common variants using logistic regression. We adjusted for age, gender, and race based on principal components. We also conducted SNP-set (Sequence) Kernel Association Test (SKAT) with common and rare variants in the gene regions with the most statistically significant SNP results. Results: Average sequencing depth was 30x and with a total of 34,548,910 variants. While SNPs in genes previously indicated in the IVIG pathway were confirmed, multiple novel SNPs in various gene regions were also statistically significant (often p&lt; 10-6; Figure-Manhattan plot). SKAT analysis suggested joint effects of multiple SNPs in individual gene regions. Conclusions: We confirmed SNPs in genes from previous reports and identified multiple novel ones, indicating plausible previous unsuspected IVIG mechanisms pathways. Potentially, functional disruption of these genes could lead to non-response. Further, a panel of these SNPs can be a prognostic tool for identifying at-risk KD patients that require therapy intensification.

Development of Single Nucleotide Polymorphism and Association Analysis with Growth Traits for Black Porgy (Acanthopagrus schlegelii).

Black porgy is an important marine aquaculture fish species whose production is at the fifth position in all kinds of marine-cultured fishes in China. In this study, Illumina high-throughput sequencing technology was used to sequence the total RNA of black porgy. Sixty-one candidate SNPs (Single Nucleotide Polymorphism) were screened out and genotyped through GATK4 (Genome Analysis ToolKit) software and MALDI-TOF MS (Matrix-Assisted Laser Desorption/ Ionization Time of Flight Mass Spectrometry). The experimental results showed that a total of sixty SNPs were successfully genotyped, with a success rate of 98.36%. The results of principal component analysis and correlation analysis of growth traits showed that body weight was the first principal component, with a cumulative contribution rate of 74%. There were significant correlations (p < 0.05) or extremely significant correlations (p < 0.01) between different growth traits. The results of genetic parameter analysis and association analysis showed that scaffold12-12716321, scaffold13-4787950, scaffold2-13687576 and scaffold290-11890 were four SNPs that met the requirement of polymorphic information content and conformed to the Hardy-Weinberg equilibrium. There were significant differences between their genotype and the phenotype of growth traits. The four SNP molecular markers developed in this research will lay a foundation for further exploration of molecular markers related to the growth traits of black porgy and will provide a scientific reference for the further study of its growth mechanisms. At the same time, these molecular markers can be applied to the production practices of black porgy, so as to realize selective breeding at the molecular level and speed up the breeding process.

Application of next-generation sequencing for the high-resolution typing of MHC-B in Korean native chicken.

The major histocompatibility complex-B (MHC-B) region of chicken is crucially important in their immunogenesis and highly diverse among different breeds, lines, and even populations. Because it determines the resistance/susceptibility to numerous infectious diseases, it is important to analyze this genomic region, particularly classical class I and II genes, to determine the variation and diversity that ultimately affect antigen presentation. This study investigated five lines of indigenous Korean native chicken (KNC) and the Ogye breed using next-generation sequencing (NGS) data with Geneious Prime-based assembly and variant calling with the Genome Analysis Toolkit (GATK) best practices pipeline. The consensus sequences of MHC-B (BG1-BF2) were obtained for each chicken line/breed and their variants were analyzed. All of the Korean native chicken lines possessed an excessive number of variants, including an ample amount of high-impact variants that provided useful information regarding modified major histocompatibility complex molecules. The study confirmed that next-generation sequencing techniques can effectively be used to detect MHC variabilities and the KNC lines are highly diverse for the MHC-B region, suggesting a substantial divergence from red junglefowl.

Targeted Sequencing of Cytokine-Induced PI3K-Related Genes in Ulcerative Colitis, Colorectal Cancer and Colitis-Associated Cancer.

Chronic relapsing inflammatory bowel disease is strongly linked to an increased risk of colitis-associated cancer (CAC). One of the well-known inflammatory carcinogenesis pathways, phosphatidylinositol 3-kinase (PI3K), was identified to be a crucial mechanism in long-standing ulcerative colitis (UC). The goal of this study was to identify somatic variants in the cytokine-induced PI3K-related genes in UC, colorectal cancer (CRC) and CAC. Thirty biopsies (n = 8 long-standing UC, n = 11 CRC, n = 8 paired normal colorectal mucosa and n = 3 CAC) were subjected to targeted sequencing on 13 PI3K-related genes using Illumina sequencing and the SureSelectXT Target Enrichment System. The Genome Analysis Toolkit was used to analyze variants, while ANNOVAR was employed to detect annotations. There were 5116 intronic, 355 exonic, 172 untranslated region (UTR) and 59 noncoding intronic variations detected across all samples. Apart from a very small number of frameshifts, the distribution of missense and synonymous variants was almost equal. We discovered changed levels of IL23R, IL12Rß1, IL12Rß2, TYK2, JAK2 and OSMR in more than 50% of the samples. The IL23R variant in the UTR region, rs10889677, was identified to be a possible variant that might potentially connect CAC with UC and CRC. Additional secondary structure prediction using RNAfold revealed that mutant structures were more unstable than wildtype structures. Further functional research on the potential variants is, therefore, highly recommended since it may provide insight on the relationship between inflammation and cancer risk in the cytokine-induced PI3K pathway.