Date of Submission

4-2023

Document Type

Thesis

Degree Name

Master of Science in Forensic Science

Department

Forensic Science

Advisor

Claire L. Glynn, Ph.D.

Committee Member

David San Pietro, Ph.D.

Committee Member

Sidney Collins

Keywords

Forensic Investigative Genetic Genealogy, DNA (STR) Analysis, Bone Marrow Transplantation, Chimerism

MeSH

DNA, Bone Marrow Transplantation, Chimerism

LCSH

Genetic genealogy, DNA--Analysis, Bone marrow--Transplantation, Chimerism

Abstract

Forensic Investigative Genetic Genealogy has rapidly evolved to become a highly effective investigative tool to assist with identifying perpetrators of violent crimes and unidentified human remains. With forensic DNA (STR) analysis, it has previously been researched that a person who has received a bone marrow transplant (BMT) may produce a multi-allelic STR profile, as both the bone marrow donor and the recipients' DNA is present. A multi-allelic STR profile can easily be misinterpreted as a mixture DNA profile, when in fact it is a chimeric DNA profile originating from a single individual. While the impact of chimerism on STR profiles has been studied previously, albeit with little published research, there is no published literature discussing the impact of chimerism on SNP profiles in a forensic context.

Eleven volunteers who received a bone marrow transplant were asked to provide buccal swab and blood samples. Each sample underwent the steps of forensic DNA analysis and STR profiles were analyzed to determine level of chimerism. It was seen that most of the genetic profiles of the BMT recipient showed a single profile for both samples provided. Although these two samples originated from the same individual, the buccal swab profile resulted in a different STR profile than the STR profile developed from the blood samples, showing either no change or full chimerism. Three volunteer's samples produced a multi-allelic profile, showing partial chimerism.

Volunteers were provided FTDNA kits and asked to submit a self-sample to the company. Only 5 out of 11 volunteers successfully received results, and these were uploaded to GEDmatch. Each volunteer kit was evaluated to determine whether the database matches were a result of the volunteer's family, their BMT donor's family, or a mixture of both families. The results demonstrated clear connections between matches and the volunteers as four out of five volunteers were able to identify familiar individuals and surnames, while listing few that were not recognizable. One volunteer, who was able to upload DNA data from pre-transplant and post-transplant, identified many familiar surnames, but many matches appeared in their post­transplant match list that did not appear in their pre-transplant matches.

Available for download on Thursday, May 14, 2026

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