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  • Posted: 12/29/2009

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Slide 8


Genetic Variation in Noncoding Regions

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Most SNPs occur in noncoding regions and do not alter genes. So most variations in the human genome have no known effect at all because they occur in noncoding regions of the DNA. In addition, there are some changes that do occur in coding and regulatory regions, yet the effect is not entirely understood. All these are silent variations.

Graphic shows that when the little green flags representing single nucleotide polymorphisms occur in noncoding regions, no known change occurs.