Slide 5

Variation in a Person's Genome

An amazing aspect of a person’s genome is that there is so little variation in the DNA sequence when the genome of one person is compared to that of another. Of the 3.2 billion bases, roughly 99.9 percent are the same between any two people. It is the variation in the remaining tiny fraction of the genome, 0.1 percent—roughly several million bases—that plays a powerful role in deterring or encouraging cancer.