#ESHREjc report: Catch 22—is PGT a number game? Efficacy of PGT and the importance of counselling

Preimplantation genetic testing (PGT) is routinely used in ART settings to test embryos for a specific monogenic condition (PGT-M), chromosome number variation (PGT-A) or structural rearrangements in chromosomes (PGT-SR). Even though the benefits of PGT-M and PGT-SR are undeniable in preventing genetic disorders in children by excluding the presence of specific genetic mutations or chromosomally unbalanced rearrangements, the efficacy of PGT-A is still controversial and the scientific community is split between proponents and opponents. The October edition of the ESHRE Journal Club discussed a paper from Sonigo et al. (2021), where a statistical model was used to predict the threshold of mature oocytes (MIIs) to obtain at least one healthy transferable embryo following PGT in carriers of fragile X syndrome (FXS). Silencing of the FMR1 gene (through an increase in CGG repeats) leads to FXS, resulting in learning disabilities or mental retardation. Female patients with an FMR1 pre-mutated allele...