Chromosomal transformation in donor cells following allogeneic bone marrow transplantation.

We report here a monosomy 7 transformation of donor cells following matched-unrelated, same sex, allogeneic bone marrow transplantation in a patient with severe congenital aplastic anemia. A PCR technique was employed to amplify microsatellite markers on chromosome 7 to confirm donor/recipient identity. We found that the transformation of monosomy 7 occurred in previously genetically normal donor cells. This study suggests that the microenvironment of the bone marrow of our patient with severe congenital aplastic anemia may have played a critical role in the development of monosomy 7 of normal donor cells and we conclude that chromosomal microsatellite marker analysis can be a valuable tool for precise donor/recipient differentiation in engraftment monitoring.