Although it is more than a decade since the first PGD for SGD was performed (Handyside et al., 1992), the complexity of the approach has so far limited its clinical application. PGD is a multidisciplinary procedure that requires combined expertise in reproductive medicine and molecular genetics (Geraedts et al., 2001). Thus, even if the numbers of centres performing PGD is increasing steadily, mainly for aneuploidy screening, only a few centres worldwide are offering PGD for SGDs as a clinical service.

To date it is estimated that PGD has been applied in over 100 different SGDs in over 1000 cycles, resulting in the birth of more than 300 unaffected children (ESHRE PGD Consortium, 2002; Sermon et al., 2005).

The PGD program at GENOMA for singe gene disorders is the product of almost 10 years of extensive protocol development including test refinement and rigorous validation.