If you've ever wondered whether there's a way to do what 23andMe wanted to do with regards to fitting patient care to risk factor relationships found in the genome, by the way, there may be. Genetically personalized medicine can already account for single-nucleotide mutations that impair a drug's function, as demonstrated in the design of different drugs for different stages in the progression of CML, a form of leukemia. The Geisinger hospital system in Pennsylvania, which treats about three million people, is participating with a company called Regeneron (PDF) in a huge longitudinal genomics study that will work with anonymized data on patient exomes from DNA samples they've volunteered. They intend to use the unaltered data to tailor health care to the patients in the study. As pioneers in the field, no doubt they'll experience problems and setbacks, but the example Geisinger sets will be an important proof of concept.