The Chimera Effect – As if DNA Interpretation Wasn’t Challenging Enough

This abstract explores a compelling sexual assault case involving a twenty-one-year-old female and her ex-boyfriend. Processing of the evidence revealed several unanticipated results, one of which was that the victim’s reference profile contained a mixture of two individuals. Further investigation uncovered that the victim had received a bone marrow transplant, with her younger sister as the donor.

This presentation delves into the impact a mixed reference sample can have on DNA interpretation in forensic casework. Specifically, the bone marrow transplant resulted in the victim having multiple mixed DNA profiles within her body. This unique scenario challenged traditional assumptions and interpretation modalities in DNA analysis, where a person’s DNA profile is expected to be single source and remain consistent across different biological samples. The presence of a mixed reference DNA profile further complicated the interpretation process and underscored the need for awareness and recognition of the effects organ transplants may have on forensic evidence.

Understanding these implications is crucial for forensic practitioners and legal professionals involved in cases where DNA evidence plays a pivotal role. By highlighting this case, the presentation aims to stimulate discussion and awareness within the forensic community regarding the complexities introduced by medical interventions, such as bone marrow transplants, thereby enhancing the accuracy and reliability of DNA analysis in criminal investigations.