Whole exome sequencing was performed on HLA-matched stem cell donors and transplant recipients to measure sequence variation contributing to minor histocompatibility antigen differences between the two. A large number of nonsynonymous single nucleoti
de polymorphisms were identified in each of the nine unique donor-recipient pairs tested. This variation was greater in magnitude in unrelated donors as compared with matched related donors. Knowledge of the magnitude of exome variation between stem cell transplant recipients and donors may allow more accurate titration of immunosuppressive therapy following stem cell transplantation.
