Journal of Molecular Diagnostics最新文献

Circulating tumor DNA (ctDNA) quantification surpasses cancer antigen 15 to 3 for metastatic breast cancer surveillance. Clinical translation, however, is limited because of uncertainties about the optimal method and clinically valid ctDNA decision thresholds. Plasma-SeqSensei Breast Cancer IVD kit (PSS) is a novel assay for ctDNA molecular counting, detecting ≥0.06% variant allele fractions in AKT1, ERBB2, ESR1, KRAS, PIK3CA, and TP53. PSS was validated against droplet digital PCR (ddPCR) in 201 samples from 16 subjects with PIK3CA/TP53-mutated cancers, longitudinally sampled for a median of 93 (range, 18 to 113) weeks, three to five weekly. PSS and ddPCR ctDNA levels correlate significantly (Spearman ρ, 0.923; 95% CI, 0.898-0.941) across 0% to 43% variant allele frequency (VAF) range. PSS predicts 12-week progression with high clinical accuracy (area under the curve, 0.848; 95% CI, 0.790-0.894). PSS validates a previously developed ddPCR classifier: <10 copies/mL (0.25% VAF); excludes >100 copies/mL (2.5% VAF); and confirms progression, with negative predictive value (95% CI) of 83% (76%-88%) and positive predictive value (95% CI) of 91% (81%-96%) (weighted κ, 0.856; 95% CI, 0.797-0.915). PSS thus confirms robust clinical thresholds (10 to 100 copies/mL, 0.25% to 2.5% VAF) for metastatic breast cancer surveillance, using absolute molecular counting.

An amplicon-based targeted next-generation sequencing (NGS) assay for the detection of gene fusions in sarcomas was developed, validated, and implemented. This assay can detect fusions in targeted regions of 138 genes and BCOR internal tandem duplications. This study reviews our experience with testing on the first 652 patients analyzed. Gene fusions were detected in 238 (36.5%) of 652 cases, including 83 distinct fusions in the 238 fusion-positive cases, 10 of which had not been previously described. Among the 238 fusion-positive cases, the results assisted in establishing a diagnosis for 137 (58%) cases, confirmed a suspected diagnosis in 66 (28%) cases, changed a suspected diagnosis in 25 (10%) cases, and were novel fusions with unknown clinical significance in 10 (4%) cases. Twenty-six cases had gene fusions (ALK, ROS1, NTRK1, NTRK3, and COL1A1::PDGFB) for which there are targetable therapies. BCOR internal tandem duplications were identified in 6 (1.2%) of 485 patients. Among the 138 genes in the panel, 66 were involved in one or more fusions, and 72 were not involved in any fusions. There was little overlap between the genes involved as 5'-partners (31 different genes) and 3'-partners (37 different genes). This study shows the clinical utility of a next-generation sequencing gene fusion detection assay for the diagnosis and treatment of sarcomas.

The use of next-generation sequencing and other high-throughput technologies in the clinical molecular diagnostics laboratory requires the application of bioinformatics pipelines and other computational tools to analyze, visualize, and store these clinical data. Clinical bioinformaticians, individuals with the skills to develop, validate, and deploy these tools in a clinical setting, are needed to ensure that these molecular diagnostic technologies can be appropriately used for clinical care. Building on existing expertise in informatics, next-generation sequencing, and clinical molecular diagnostics, the Association for Molecular Pathology has generated a series to establish an initial clinical bioinformatician body of knowledge. These articles cover the potential roles of the clinical bioinformatician, assist molecular laboratory and clinical bioinformatics directors in understanding the various roles of the clinical bioinformatics team members, and provide guidance regarding the competencies and skill sets required. The three articles within this Body of Knowledge cover the following knowledge cores: i) Molecular Diagnostics, ii) Clinical Bioinformatics, Software, and Database Knowledge, and iii) Clinical Laboratory Regulation and Data Security. Many of the topics covered in these articles are broad and rapidly evolving; therefore, this Association for Molecular Pathology Clinical Bioinformatician Body of Knowledge article series is designed to provide an initial framework for the core bioinformatics skills required to function successfully within a molecular diagnostic laboratory.

Consanguinity, prevalent in certain populations because of cultural and social factors, significantly increases the risk of genetic autosomal recessive disorders. In Lebanon, consanguineous marriages constitute 35.5% of unions, with first cousin marriages being the most common. This study aims to develop a model to predict consanguinity status using total runs of homozygosity (ROH) size derived from exome sequencing data. In this study, a cohort of 784 Lebanese individuals was analyzed, with consanguinity labels assigned based on pedigree information. ROHs were detected from exome sequencing data using AutoMap. The analysis focused on 521 subjects for whom the consanguinity or nonconsanguinity label was clearly determined, leading to the development of two logistic regression models: one including outliers (accuracy, 91%) and one excluding them (accuracy, 94%). The second model established specific ROH thresholds for categorizing consanguinity: nonconsanguineous [<40.28 megabases (Mb)], uncertain (40.28 to 79.17 Mb), probable consanguinity (79.17 to 118.06 Mb), and consanguineous (>118.06 Mb). This study provides a valuable tool for clinical genetics in populations with high consanguinity rates, offering insights into the genetic risks associated with consanguinity and aiding in the identification and counseling of affected individuals. Moreover, the current findings underline the importance of population-specific thresholds in accurately assessing consanguinity status.

Pharmacogenetic-guided prescribing can lead to more accurate medicine selection and dosing, improving patient outcomes and leading to better use of health care budgets. Loss-of-function variants in CYP2C19 influence an individual's ability to metabolize clopidogrel, increasing the risk of secondary vascular events following ischemic stroke and percutaneous coronary intervention. In acute clinical contexts, centralized laboratory-based testing is too slow to inform timely clinical decision-making. This work reports the development and analytical validation of the Genedrive CYP2C19 ID Kit, which provides rapid point-of-care genotyping from a buccal swab in approximately 1 hour. Buccal samples were collected from a total of 204 individuals between September 2023 and July 2024, alongside a blood or saliva sample for comparison with laboratory testing. In the final cohort of 202 patients, all point-of-care results were concordant with laboratory testing. In this assessment, the sensitivity and specificity of the CYP2C19 ID Kit was 100% (95% CI, 95.0%-100%) and 100% (95% CI, 97.2%-100%), respectively. The failure rate of the CYP2C19 ID Kit was 0.98%. This study confirms the analytical validity of the Genedrive CYP2C19 ID Kit. The Genedrive system is able to provide an accurate, rapid, noninvasive alternative to standard laboratory testing and can be used as a point-of-care test in the clinical environment.

Kirsten rat sarcoma viral oncogene homolog (KRAS) somatic mutations occur in 30% to 40% of patients with colorectal cancer (CRC). These were thought to equally affect prognosis and resistance to anti-epidermal growth factor receptor agents; however, recent data show the activity of KRAS-G12C and pan-RAS inhibitors. The effects of uncommon KRAS (uKRAS) variants are largely unexplored. The distribution and pathogenicity of uKRAS mutations and their relationship with patients' clinicopathologic features were assessed. A total of 2427 CRCs were profiled for KRAS using next-generation sequencing (NGS). The study and control groups included patients with uKRAS (<1% frequency in CRC data sets on cBioPortal) and canonical KRAS mutations, respectively. In silico protein structure modifications and prediction analyses were performed by using PyMOL, trRosetta, and PolyPhen-2. uKRAS mutations affected 35 cases (1.5%), with G13C (28.6%), G12R (20%), and V14I (8.6%) being most common. Missense mutations (D33E, G12W, G12F, Q22H, Q61L, and L19F) occurred in nine cases (25.7%). Duplications (G10dup and L52_G60dup) affected two cases. Pathogenicity analyses showed that G12W, Q22R, L56V, and A130I mutations are probably damaging, with scores between 0.928 and 1.000. No differences were seen in clinicopathologic features. uKRAS mutants had lower event-free survival but no difference in overall survival compared with controls. Although these data are hypothesis generating and need further confirmation, they highlight the importance of NGS-based profiling to identify CRC patients with uKRAS mutations as candidates for personalized therapy.

Poly (adenosine diphosphate-ribose) polymerase (PARP) inhibitors represent a significant advancement in the treatment of epithelial ovarian cancer, triple-negative breast cancer, pancreatic cancer, and castrate-resistant prostate cancer, and they are poised to improve treatment in an increasing number of other cancer types. PARP inhibitor efficacy as monotherapy has been primarily observed in tumors with deleterious genetic variants in genes involved in the homologous recombination repair pathway. Tumors without these variants have also been shown to respond; notably, those with hypermethylation at all alleles of the BRCA1 or RAD51C promoter can respond to PARP inhibitors. These epigenetic biomarkers therefore represent a patient population that may also benefit from this targeted therapy. However, no robust test has been conducted to identify these biomarkers in routine clinical specimens that is amenable to implementation for decentralized testing. This study describes the analytical and clinical validation of a BRCA1 and RAD51C promoter methylation test that can be run with a single-day library preparation workflow for sequencing on any next-generation sequencing platform. The results show that this test can accurately quantitate the level of promoter methylation at the BRCA1 and RAD51C genes using formalin-fixed, paraffin-embedded samples, even when the extracted DNA is extremely degraded or the input amount is limited. This test increases the precision of diagnostic tests aimed at identifying patients who are likely and unlikely to respond to PARP inhibitor therapy.

The adoption of comprehensive genomic profiling in oncology has rapidly increased the demand for standardized tumor sample processing in diagnostic laboratories. Automation of DNA and RNA library preparation workflows offers the possibility to scale-up and standardize sample processing. We report on the clinical implementation of the automated TruSight Oncology 500 High-Throughput library preparation workflow from formalin-fixed, paraffin-embedded tumor samples using the Biomek i7 hybrid Workstation. Using the same input amount, the automated workflow was validated against manual library preparation. Quality control metrics (total and mapped reads, median insert size, and median exon coverage) and the detection of tumor mutational burden, a complex biomarker, were concordant between the manual and automated workflows. The automated workflow was implemented on a total of 2997 pan-cancer clinical samples to detect genomic variants and complex biomarkers. Workflow automation resulted in a 4-fold reduction in hands-on time and a 1.7-fold reduction in total runtime compared with manual library preparation (6 hours vs. 23 hours; 24 hours vs. 42.5 hours, respectively) for a 48 DNA + 48 RNA sample batch. The automated workflow required one technician versus three technicians to manually prepare the same number of libraries. This study shows that implementation of the automated TruSight Oncology 500 High-Throughput workflow significantly reduced hands-on time and processing time per sample compared with manual library preparation.

Accurate monitoring of minimal residual disease (MRD) is crucial for effective management of patients with acute myeloid leukemia (AML). This study aims to validate MRD detection of the seven most common IDH1 and IDH2 mutations in patients with AML using a QuantStudio 3D digital PCR platform. This assay demonstrated a high concordance for the variant allele frequencies between digital PCR and next-generation sequencing assays. Precision analysis revealed only small variation (<0.5 log10) for all mutations near or at the limit of detection level. This validation also showed a great reproducibility for interrun and intrarun comparisons (28 runs, variation ranges from 0 to 0.48 log10), ensuring comparable results for patient follow-ups. The limit of detection was determined to be 0.1% for all mutations, except the IDH2 R140Q mutation, which was 0.5%. Controls and acceptable ranges were also established for each mutation during validation. This study suggests that the QuantStudio 3D digital PCR assay is a quantitative, sensitive, and reproducible platform for monitoring MRD in patients with AML.

BCR::ABL1 digital PCR is a promising technique for the quantification of deep molecular responses (DMRs) in chronic myeloid leukemia. It provides an improved precision and sensitivity compared with conventional real-time quantitative PCR (qPCR), which is particularly relevant in the context of prediction of successful treatment-free remission. This study assessed the feasibility of BCR::ABL1 digital PCR in clinical practice. A total of 168 DMR samples of patients with chronic myeloid leukemia aiming for a treatment-free remission attempt were assessed by both digital PCR and qPCR. Digital PCR was performed with the droplet-based Bio-Rad QXDx BCR-ABL %IS assay, using eight replicates per sample. qPCR was performed with the fully automized Cepheid Xpert BCR-ABL Ultra assay. Various technical and practical aspects of BCR::ABL1 quantification using digital PCR were assessed. The reported limit of detection of the qPCR is molecular response 4.5, requiring an equivalent of 32,000 ABL1 transcripts. Using digital PCR, a median number of ABL1 of approximately 300,000 were obtained. BCR::ABL1 was quantifiable by digital PCR in 68% of the samples below qPCR's limit of detection. In addition, e13a2 and e14a2 BCR::ABL1 transcript types could be discriminated based on the mean fluorescence intensity of BCR::ABL1-positive droplets. BCR::ABL1 digital PCR is feasible for DMR quantification in clinical practice and offers an increased sensitivity over qPCR.