Preimplantation genetic diagnosis for cystic fibrosis: the Montpellier center's 10‐year experience

This study provides an overview of 10 years of experience of preimplantation genetic diagnosis ( PGD ) for cystic fibrosis ( CF ) in our center. Owing to the high allelic heterogeneity of CF transmembrane conductance regulator ( CFTR ) mutations in south of France, we have set up a powerful universal test based on haplotyping eight short tandem repeats ( STR ) markers together with the major mutation p.Phe508del. Of 142 couples requesting PGD for CF , 76 have been so far enrolled in the genetic work‐up, and 53 had 114 PGD cycles performed. Twenty‐nine cycles were canceled upon in vitro fertilization ( IVF ) treatment because of hyper‐ or hypostimulation. Of the remaining 85 cycles, a total of 493 embryos were biopsied and a genetic diagnosis was obtained in 463 (93.9%), of which 262 (without or with a single CF ‐causing mutation) were transferable. Twenty‐eight clinical pregnancies were established, yielding a pregnancy rate per transfer of 30.8% in the group of seven couples with one member affected with CF , and 38.3% in the group of couples whose both members are carriers of a CF ‐causing mutation [including six couples with congenital bilateral absence of the vas deferens ( CBAVD )]. So far, 25 children were born free of CF and no misdiagnosis was recorded. Our test is applicable to 98% of couples at risk of transmitting CF .