Non-HLA Genetics and Application to Living Donor Candidates.

Purpose of Review: This review examines the expanding role of non-human leukocyte antigen (non-HLA) genetic factors in kidney transplantation, with a particular focus on their implications for living donor evaluation and outcomes. It emphasizes the potential of genetic testing to improve risk stratification beyond conventional HLA matching, especially for donor candidates with a family history of hereditary kidney disease. Recent Findings: Non-HLA genetic mismatches, including single nucleotide variants affecting minor histocompatibility antigens, can drive alloimmune responses, leading to graft rejection and failure even in HLA-matched transplants. The presence of non-HLA antibodies further contributes to adverse immunological outcomes. Genetic testing in related living donors can uncover monogenic kidney diseases, enabling early identification of at-risk individuals and enhancing donor safety. While polygenic risk scores and gene panels show promise in predicting complications and guiding post-transplant care, most genome-wide association studies have focused on recipients. There remains a significant gap in understanding how donor-specific genetic factors influence post-donation kidney function and long-term health outcomes. Summary: The integration of non-HLA genetic testing into living donor evaluation supports a precision medicine approach to kidney transplantation, offering improved risk assessment and donor-recipient matching. As the field advances, longitudinal studies and robust data collection, particularly around donor genetics, are essential to optimize transplant outcomes, inform clinical decision-making, and uphold ethical standards in donor care.