[Prenatal stem cell transplantation: from bench to bedside].

Prenatal stem cell transplantation is a novel, promising therapeutic option for genetic disorders, which is now at the edge of moving from preclinical research into clinical application. The first clinical experience shows that inborn diseases, which lead to a severe immunodeficiency, can be treated successfully inutero. No therapeutic success has been achieved in genetic disorders which do not severely affect the immune system. Therefore, new strategies to improve the success are being developed, including e.g., graft modification, prenatal conditioning of the fetus, postnatal re-transplantation after prenatal induction of immune tolerance, and fetal gene therapy using autologous fetal stem cells. The use of non-hematopoietic (e.g. mesenchymal) or pluripotent stem cells will most probably lead to an expansion of the spectrum of indications in genetic diseases for this novel treatment. At the same time, however, ethical implications, in particular regarding fetal gene therapy and the use of pluripotent stem cells must be evaluated.