Polymorphisms in the non-coding region of the human mitochondrial genome in unrelated plateletapheresis donors

Human mitochondrial DNA polymorphisms are unique targets to discriminate nu cleated cells and platelets between donor and recipient in the setting of t ransplantation or transfusion. We have previously used this approach to dis criminate allogeneic platelets from autologous platelets after transfusion. In the present study, we used DNA sequencing to investigate polylmorphisms present in two of the hypervariable segments (HVR1 and HVR2) found within the non-coding region of the mitochondrial genome among 100 plateletapheres is donors, Alignments were made with the Cambridge Reference Sequence (CRS) for human mitochondrial DNA (mtDNA), Combining the sequencing information of HVR1 and HVR2 we could demonstrate that, of the 100 investigated mtDNA s amples, none was identical to the CRS. We found a total of 2-17 polymorphis ms per donor in the investigated regions, most of them were basepair substi tutions (563) and insertions (151), No deletions were found. Sixty-six of t he 110 detected polymorphisms were detected in more than one sample, Seven polymorphisms are newly described and have not been published in the Mitoma p database. Our results demonstrate that polymerase chain reaction analysis of the many polymorphisms found in the hypervariable region of mitochondri al DNA represents a more informative target than previously described mitoc hondrial polymorphisms for discriminating donor-recipient cells after trans fusion or transplantation.