Background: Copy number variants (CNVs) play a significant role in human heredity and disease. However, sensitive and specific characterization of germline CNVs from NGS data has remained challenging, particularly for hybridization-capture data in which read counts are the primary source of copy number information.

Results: We describe two algorithmic adaptations that improve CNV detection accuracy in a Hidden Markov Model (HMM) context. First, we present a method for computing target- and copy number-specific emission distributions. Second, we demonstrate that the Pointwise Maximum a posteriori (PMAP) HMM decoding procedure yields improved sensitivity for small CNV calls compared to the more common Viterbi HMM decoder. We develop a prototype implementation, called Cobalt, and compare it to other CNV detection tools using sets of simulated and previously detected CNVs with sizes spanning a single exon to a full chromosome.

Conclusions: In both the simulation and previously detected CNV studies Cobalt shows similar sensitivity but significantly fewer false positive detections compared to other callers. Overall sensitivity is 80-90% for deletion CNVs spanning 1-4 targets and 90-100% for larger deletion events, while sensitivity is somewhat lower for small duplication CNVs.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9297596PMC
http://dx.doi.org/10.1186/s12859-022-04820-wDOI Listing

Publication Analysis

Top Keywords

copy number
12
number variants
8
cnv detection
8
cnvs
5
algorithmic improvements
4
improvements discovery
4
discovery germline
4
copy
4
germline copy
4
variants next-generation
4

Similar Publications

Objective: This study aims to improve genetic diagnosis in childhood onset epilepsy with neurodevelopmental problems by utilizing RNA sequencing of fibroblasts to identify pathogenic variants that may be missed by exome sequencing and copy number variation analysis.

Methods: We enrolled 41 individuals with childhood onset epilepsy and neurodevelopmental problems who previously had inconclusive genetic testing. Fibroblast samples were cultured and analyzed using RNA sequencing to detect aberrant expression, aberrant splicing, and monoallelic expression using the Detection of RNA Outlier Pipeline (DROP) pipeline.

View Article and Find Full Text PDF

Comprehensive evaluation of genomic and functional assays for homologous recombination deficiency with high-grade epithelial ovarian cancer: Platinum sensitivity and prognosis.

Int J Gynecol Cancer

January 2025

Fudan University Shanghai Cancer Center, Department of Gynecologic Oncology, Shanghai, China; Fudan University, Shanghai Medical College, Department of Oncology, Shanghai, China. Electronic address:

Objective: Homologous recombination deficiency assays, guiding treatment of poly (adenosine diphosphate ribose) polymerase inhibitors, are increasingly applied in clinics. This study aimed to evaluate the predictive performance of homologous recombination deficiency status at genomic and functional perspective on the efficacy of platinum-based chemotherapy in ovarian cancer.

Methods: Between 2016 and 2019, 134 patients with high-grade ovarian cancer were retrospectively analyzed.

View Article and Find Full Text PDF

CD7-targeted chimeric antigen receptor-T (CAR-T) cell therapy has shown great promise in the treatment of relapsed/refractory T-cell acute lymphoblastic leukemia (T-ALL). In this study, we reported a case of a 34-year-old male patient with T-ALL who finally developed multi-line drug resistance and refractoriness after multiple lines of high-intensity chemotherapy. After physician evaluation, this patient received allogeneic hematopoietic stem cell transplantation (allo-HSCT).

View Article and Find Full Text PDF

Background: Whole exome sequencing (WES) technology has been increasingly used for the etiological diagnosis of fetuses with ultrasound anomalies. In this article, we report a novel deletion compound combined with a causative variant in gene leading to short-rib thoracic dysplasia 7 (SRTD7) with or without polydactyly using WES.

Methods: This study involved a Chinese fetus with clinical features of skeletal dysplasia on ultrasound imaging, in whom chromosome abnormalities and copy number variants (CNVs) were detected by chromosomal microarray analysis (CMA), and sequence variants were detected by WES.

View Article and Find Full Text PDF

Transcription near arrested DNA replication forks triggers ribosomal DNA copy number changes.

Nucleic Acids Res

January 2025

Laboratory of Genome Regeneration, Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo113-0032, Japan.

DNA copy number changes via chromosomal rearrangements or the production of extrachromosomal circular DNA. Here, we demonstrate that the histone deacetylase Sir2 maintains the copy number of budding yeast ribosomal RNA gene [ribosomal DNA (rDNA)] by suppressing end resection of DNA double-strand breaks (DSBs) formed upon DNA replication fork arrest in the rDNA and their subsequent homologous recombination (HR)-mediated rDNA copy number changes during DSB repair. Sir2 represses transcription from the regulatory promoter E-pro located near the fork arresting site.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!