HUMAN CHIMERISM: A SYSTEMATIC REVIEW OF MECHANISMS, CASES, AND CLINICAL IMPLICATIONS

Human chimerism represents a fascinating biological phenomenon where an individual harbors genetically distinct cell populations originating from different zygotes or external sources. This systematic review examines the various forms of human chimerism, their underlying mechanisms, documented cases, and clinical implications. Through comprehensive analysis of published literature, we identify four primary categories: natural chimerism (including twin twin transfusion and maternal fetalmicrochimerism), artificial chimerism (transplantation induced), blood chimerism, and tetragametic chimerism. The review highlights the diagnostic challenges, forensic implications, and therapeutic considerations associated with chimeric conditions. Our findings demonstrate that chimerism, while rare, has significant implications for medical practice, legal proceedings, and our understanding of human biology.