Clinical and Technical Overview of Preimplantation Genetic Diagnosis for Fragile X Syndrome: Experience at the University Hospital Virgen del Rocio in Spain

Abstract

Fragile X syndrome (FXS) accounts for about one-half of cases of X-linked intellectual disability and is the most common monogenic cause of mental impairment. Reproductive options for the FXS carriers include preimplantation genetic diagnosis (PGD). However, this strategy is considered by some centers as wasteful owing to the high prevalence of premature ovarian failure in FXS carriers and the difficulties in genetic diagnosis of the embryos. Here we present the results of our PGD Program applied to FXS, at the Department of Genetics, Reproduction and Fetal Medicine of the University Hospital Virgen del Roc´ıo in Seville. A total of 11 couples have participated in our PGD Program for FXS since 2010. Overall, 15 cycles were performed, providing a total of 43 embryos. The overall percentage of transfers per cycle was 46.67% and the live birth rate per cycle was 13.33%. As expected, these percentages are considerably lower than the ones obtained in PGD for other pathologies. Our program resulted in the birth of 3 unaffected babies of FXS for 2 of the 11 couples (18.2%) supporting that, despite the important drawbacks of PGD for FXS, efforts should be devoted in offering this reproductive option to the affected families.