Preimplantation diagnosis for immunodeficiencies.

Preimplantation genetic diagnosis (PGD) has become an established procedure for the detection of single gene disorders, and has recently been performed together with human leukocyte antigen (HLA) typing for couples with children affected by genetic disorders that require HLA-identical stem cell transplantation therapy. For these couples, PGD can ensure the birth of an unaffected child, and because HLA-matched stem cell transplantation improves or completely restores the immune system, this child may also serve as a potential stem cell donor for affected siblings. This paper presents the first cumulative experience (18 cycles) of PGD for detection of the following immunodeficiencies: Wiscott-Aldrich syndrome, X-linked hyper-IgM syndrome (HIGM), X-linked hypohidrotic ectodermal dysplasia with immune deficiency (HED-ID), ataxia telangiectasia and Omenn syndrome, resulting in the transfer of unaffected embryos in 13 cycles and the birth of seven unaffected children, with one healthy pregnancy ongoing.

Preimplantation HLA typing with aneuploidy testing.

Preimplantation HLA typing has been introduced for the treatment of affected siblings, requiring HLA-identical stem cell transplantation. This was applied either in combination with preimplantation genetic diagnosis (PGD) to ensure that the preselected HLA-matched embryos were also free of the genetic disorder, or without PGD, with the only purpose of selecting and transferring the HLA-matched embryos. Because patients requesting preimplantation HLA typing are usually of advanced reproductive age, aneuploidy testing allows not only the avoidance of the birth of children with chromosomal disorders, but also improvement of the reproductive outcome, which is still not sufficiently high in preimplantation HLA typing at the present time.