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Updated: Jun 2, 2026

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Array Comparative Genomic Hybridization (Array CGH) for Detection of Genomic Copy Number Variants
Published on: February 21, 2015
Comprehensive assessment of array-based platforms and calling algorithms for detection of copy number variants
Dalila Pinto1, Katayoon Darvishi, Xinghua Shi
1The Centre for Applied Genomics, The Hospital for Sick Children, Toronto, Ontario, Canada.
Nature Biotechnology
|May 10, 2011
Summary
Copy number variant (CNV) detection shows low concordance (<50%) and reproducibility (<70%) across platforms and tools. However, large CNVs are still detectable for clinical diagnostics after data curation.
Area of Science:
- Genomics
- Bioinformatics
- Molecular Biology
Background:
- Copy number variants (CNVs) are crucial in genetic variation and disease.
- Standardized methods for CNV detection across different microarray platforms are lacking.
- Variability in CNV calling can impact research and clinical diagnostics.
Purpose of the Study:
- To systematically compare CNV detection across eleven microarrays.
- To evaluate data quality, CNV calling, reproducibility, and concordance.
- To assess breakpoint accuracy and the impact of analysis tool variability.
Main Methods:
- Comparative analysis of CNV detection using eleven microarray platforms.
- Evaluation of data quality, reproducibility, and concordance metrics.
- Assessment of breakpoint accuracy and analysis tool performance.
Main Results:
- CNV calling concordance between different analytic tools was typically less than 50%.
- Reproducibility in replicate experiments was below 70% for most platforms.
- Large CNVs, primarily in complex genomic regions, showed poor reproducibility but are manageable via clinical data curation.
Conclusions:
- Significant variability exists in CNV detection across platforms and tools, emphasizing the need for careful experimental design and data curation.
- Despite variability, large CNVs can be reliably detected for clinical diagnostics.
- The presented CNV resource facilitates independent data evaluation and algorithm benchmarking.
Related Concept Videos
Comparing Copy Number Variations and SNPs
Sequencing of the human genome has opened up several best-kept secrets of the genome. Scientists have identified thousands of genome variations that exist within a population. These variations can be a single nucleotide or a larger chromosomal variation.
Copy number variations or CNVs are the structural variations that cover more than 1kb of DNA sequence. The single nucleotide polymorphism (SNP), on the other hand, is a single nucleotide change or a point mutation that is found in more than 1%...
Copy number variations or CNVs are the structural variations that cover more than 1kb of DNA sequence. The single nucleotide polymorphism (SNP), on the other hand, is a single nucleotide change or a point mutation that is found in more than 1%...
DNA Microarrays
Microarrays are high-throughput and relatively inexpensive assays that can be automated to analyze large quantities of data at a time. They are used in genome-wide studies to compare gene or protein expression under two varied conditions, such as healthy and diseased states. Microarrays consist of glass or silica slides on which probe molecules are covalently attached through surface functionalization. Most commonly, the slides are prepared through the chemisorption of silanes to silica...
Genome Copying Errors
DNA replication is a well-evolved process that copies millions of base pairs with high fidelity during each cell division. Occasionally a wrong base or a long stretch of wrong bases may get added to the daughter strands. If the errors are left unchecked, cells might accumulate several mutations that might endanger theirĀ survival. Therefore, the copying errors are checked and repaired at three levels.

