There is value to patients, clinicians and researchers from having a single electronic health record data standard that allows an integrated view, including genotype and phenotype data. However, it is important that this integrated view of the data is not created through a single database because privacy breaches increase with the number of users, and such breaches are more likely with a single data warehouse. Furthermore, a single user interface should be avoided because each end user requires a different user interface. Finally, data sharing must be controlled by the patient, not the other end users of the data. A preferable alternative is a federated architecture, which allows data to be stored in multiple institutions and shared on a need-to-know basis. The data sharing raises questions of ownership and stewardship that require social and political answers, as well as consideration of the clinical and scientific benefits.