What is copy number variation (CNV)?

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Multiple Choice

What is copy number variation (CNV)?

Explanation:
Copy number variation refers to differences between individuals in how many copies of a particular DNA segment they have. This means some people may have deletions (missing copies) or duplications (extra copies) of stretches of the genome. These structural changes can range from thousands to millions of bases and can affect gene dosage and phenotype. This is distinct from single-nucleotide changes, which are SNPs. It’s also not about balanced rearrangements like inversions or translocations, which do not change the total copy number. Nor is CNV simply a change in gene expression level; CNV is a DNA-level difference in copy number that can influence expression as a downstream effect. Detecting CNVs is commonly done with methods such as array CGH, SNP arrays, or sequencing-based depth analyses.

Copy number variation refers to differences between individuals in how many copies of a particular DNA segment they have. This means some people may have deletions (missing copies) or duplications (extra copies) of stretches of the genome. These structural changes can range from thousands to millions of bases and can affect gene dosage and phenotype. This is distinct from single-nucleotide changes, which are SNPs. It’s also not about balanced rearrangements like inversions or translocations, which do not change the total copy number. Nor is CNV simply a change in gene expression level; CNV is a DNA-level difference in copy number that can influence expression as a downstream effect. Detecting CNVs is commonly done with methods such as array CGH, SNP arrays, or sequencing-based depth analyses.

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