Molecular-based identity testing following bone marrow transplantation is based on the fact that the patient and the bone marrow donor each have a unique genetic makeup. By analyzing the DNA in the patient’s bone marrow after transplantation, it is possible to quantify the ratio of patient to donor DNA in the sample bone marrow. This information is a direct measure of the success of a bone marrow transplant and can be used as a prognostic tool for relapse. In determining twin zygosity, identity testing is based on the fact that monozygotic twins have exactly the same genetic makeup, while dizygotic twins do not.
To perform the bone marrow studies, we require a small sample of the patient’s bone marrow (usually 3-4 cc’s but can vary depending upon white blood cell count) as well as a peripheral blood sample (5 cc’s) taken prior to the transplant. We work closely with oncologists and hospitals to coordinate this testing. To perform the twin zygosity studies, we require 5 cc’s of peripheral blood from each twin.
If you have any questions or concerns regarding DNA-based identity testing, or if you wish to schedule a blood draw, please contact us.