Medical and social perspectives of PGD for single gene disorders and human leukocyte antigen typing

Preimplantation genetic diagnosis (PGD) for single gene disorders combined with human leukocyte antigen (HLA) typing has recently emerged as a therapeutic tool. For couples who are at risk of passing on a genetic disease to their offspring, preimplantation embryos can be selected according to their genetic status as well as a possible HLA matching with the affected sibling. Stem cells from the resulting baby's umbilical cord blood have, therefore, a great therapeutic value for haematopoietic and other life threatening diseases, as stem cells in the cord blood from a HLA-compatible newborn can be used for transplantation without graft rejection, thus saving an affected child's life. However, apart from being a valuable treatment option, there exist several medical and social aspects that should be evaluated and discussed. From the ethical and the social aspects, although PGD for single gene disorders is well defined and accepted, application of PGD combined with HLA typing is less obvious and under extensive debate. This article is aimed at summarizing the current results and limitations of PGD with HLA typing that are related to the successful medical outcome. It further discusses the ethical and social issues that have recently been raised on the application of this technique.