Gene variants in noncoding regions and their possible consequences.

Human biodiversity or individual traits are not well explained by exonic mutations of all 20,000 known human genes. Accumulating evidence has demonstrated that not all noncoding regions are junk DNA sequences, and that some functionally important noncoding variants contribute significantly to altered gene expression, qualitatively or quantitatively. Thus, functional profiling or clinical relevance of noncoding variations should not be underestimated or ignored. To validate these concepts, some important examples are discussed further in this short review.