Copy Number Variation in the Human Genome


Copy number changes involving dosage‐sensitive genes are well‐known causes of human genetic diseases and inherited syndromes. Genome‐wide analytical techniques such as array comparative genomic hybridization (aCGH), Single nucleotide polymorphism (SNP) genotyping and end‐sequence comparison of large insert clones have revealed that polymorphic copy number variations (CNVs), manifesting as duplications or deletions, represent normal variants that contribute to human genomic diversity. Not all CNVs in the human genome have so far been discovered. However, it is already clear that CNVs contribute as much to human genomic variation as SNPs. Since many human CNVs contain genes, the expression differences associated with these genes are very likely to influence normal phenotypic variation. Further, since not all CNVs will turn out to be neutral variants, at least some of them are expected to alter drug metabolism or to influence disease predisposition as is already evident in the context of human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) susceptibility, Crohn's disease and immunologically mediated glomerulonephritis.

Keywords: copy number; genome diversity; segmental duplications

Figure 1.

Contribution of differentially sized CNVs to human genomic structural diversity according to Eichler (2006). Fine‐scale deletions vary in size from ∼0.5 to 10 kb whereas large‐scale variations encompass >50 kb with intermediate‐sized variations spanning ∼6–50 kb.



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Kehrer‐Sawatzki, Hildegard(Dec 2007) Copy Number Variation in the Human Genome. In: eLS. John Wiley & Sons Ltd, Chichester. [doi: 10.1002/9780470015902.a0020824]