In 1996, I argued that the recommendation by the Institute of Medicine (IOM) to inform women when tests reveal misattributed paternity and not to disclose this information to the women's partners was morally wrong. I argued in favor of disclosure to both parties. It is a position that I still hold. But claims of misattributed paternity are not 'incidental findings' as it was called in the old genetics literature, but a rather serious indictment of biological infidelity. In this paper I argue that the tests used by transplant programs for living donor-recipient compatibility are inadequate to accurately determine misattributed paternity. Further I argue that it is not the responsibility of the transplant community to undertake such serious forensic evaluations. Genetic inconsistencies in ABO and HLA inheritance should be reported as variations. Families who want further clarification should be referred to a genetic professional.