The past 60 years have witnessed remarkable progress in genetics and genomics from the description of the DNA double helix by Watson and Crick1 to the release of the first draft sequence of the human genome in 20012,3 and the successful completion of the human genome project in 2003.4 From that time, there has been increasing hope and expectation that, as soon as the cost of sequencing the whole genome could become affordable, the promise of personalized medicine would be fulfilled.