Copy Number Variation

Single-nucleotide polymorphisms (SNPs) have become the focus of a large number of studies designed to identify critical differences in DNA sequence, which contribute to phenotypic variation for specific traits. However, only a modest degree of phenotypic variation has been explained by single-nucleotide polymorphisms. This has led to broader hypotheses regarding the potential genetic basis of this "missing heritability." Copy number variation (CNV) has been proposed as one other type of genetic variation that contributes to phenotypic variance. CNVs, including duplications and deletions, can influence gene expression by disrupting gene coding sequences, perturbing long-range gene regulation, or altering gene dosage. Through these mechanisms, CNVs are shown to affect susceptibility to human diseases. In this chapter, we introduce some common methods for CNVs detection, and discuss the recent studies about the relationship between CNVs and human diseases. Finally, we discuss the relationship between CNVs and osteoporosis in detail.