Preimplantation genetic diagnosis

• A doctor practising in a multidisciplinary centre for prenatal diagnosis has to confirm that, in view of family antecedents, a couple has a strong probability of giving birth to a child suffering from a genetic disease recognised as incurable at the time of diagnosis.
• The anomaly or anomalies responsible for this disease have previously been identified either in one of the parents or in one of his or her immediate ascendants (in the case of a seriously disabling disease with late onset that could be prematurely life-threatening).
• The sole purpose of the diagnosis is to screen for the disease and ways of preventing it or treating it.
• The consent of both members of the couple has been obtained in writing. In the event of a positive diagnosis of an embryo, both members of the couple can give consent for the affected embryo, which normally would be destroyed, to be the subject of research.

Preimplantation genetic diagnosis can only be performed in an institution specifically authorised for the purpose by the Agence de la biomédecine, after consulting its Advisory Board, and by practitioners who are also approved by the Agence.

A double diagnosis (i.e. preimplantation genetic diagnosis combined with HLA typing) is intended to enable a child to be conceived who is free of a genetic disease from which his or her elder sibling suffers and who would be able to help treat the older sick child significantly thanks to cord cells collected from the umbilical cord and/or bone marrow (at a later stage). The request for a diagnosis, which emanates from the couple, is passed on to the Agence de la biomédecine by the multidisciplinary centre for prenatal diagnosis treating the couple. On a case-by-case basis, the Agence can authorise a double diagnosis if it is justified by the situation of the couple and it satisfies the conditions stipulated in the law :

• The couple must have given birth to a child affected by a genetic disease that will probably entail death in early childhood and recognised as incurable at the time of diagnosis.
• The child’s chances of survival can be improved significantly by a cord blood transplant.
• The only purposes of the diagnosis are screening for the genetic disease and the means of preventing it and treating it, on the one hand, and enabling the application of the therapy described, on the other.