Evaluation of PCR-based preimplantation genetic diagnosis applied to monogenic diseases: a collaborative ESHRE PGD consortium study

Abstract

Preimplantation genetic diagnosis (PGD) for monogenic disorders currently involves polymerase chain reaction (PCR)-based methods, which must be robust, sensitive and highly accurate, precluding misdiagnosis. Twelve adverse misdiagnoses reported to the ESHRE PGD-Consortium are likely an underestimate. This retrospective study, involving six PGD centres, assessed the validity of PCR-based PGD through reanalysis of untransferred embryos from monogenic-PGD cycles. Data were collected on the genotype concordance at PGD and follow-up from 940 untransferred embryos, including details on the parameters of PGD cycles: category of monogenic disease, embryo morphology, embryo biopsy and genotype assay strategy. To determine the validity of PCR-based PGD, the sensitivity (Se), specificity (Sp) and diagnostic accuracy were calculated. Stratified analyses were also conducted to assess the influence of the parameters above on the validity of PCR-based PGD. The analysis of overall data showed that 93.7% of embryos had been correctly classified at the time of PGD, with Se of 99.2% and Sp of 80.9%. The stratified analyses found that diagnostic accuracy is statistically significantly higher when PGD is performed on two cells versus one cell (P ¼ 0.001). Se was significantly higher when multiplex protocols versus singleplex protocols were applied (P ¼ 0.005), as well as for PGD applied on cells from good compared with poor morphology embryos (P ¼ 0.032). Morphology, however, did not affect diagnostic accuracy. Multiplex PCR-based methods on one cell, are as robust as those on two cells regarding false negative rate, which is the most important criteria for clinical PGD applications. Overall, this study demonstrates the validity, robustness and high diagnostic value of PCR-based PGD.

Fetal Reduction: 25 Years' Experience

“…With increasing use of PGD as part of the IVF process, many patients question if traditional CVS still has application in reduction decisions [58]. Our experience has been that over the past 5 years, there has been about a 2-3% discordancy between PGD results and those we have seen on CVS - with chromosomal being higher than mendelian [38].…”

Recent advances in preimplantation genetic diagnosis and screening

“…Polymerase chain reaction (PCR) is the first technique in PGD and had been developed to detect many genetic abnormalities such as single-gene mutations [3,[25][26][27], chromosomal imbalances [28], and mitochondrial mutations [29]. Likewise, fluorescence in-situ hybridization (FISH) had been performed to screen aneuploidy and chromosomal translocation for many years [30][31][32][33][34][35][36].…”

Live births after simultaneous avoidance of monogenic diseases and chromosome abnormality by next-generation sequencing with linkage analyses

“…Eliminating these errors is a major challenge for PGD. Linkage analysis has become a standard method of circumventing this problem (18,19) by detecting short tandem repeats (STR) or by karyomapping with an SNP array (20)(21)(22)(23)(24) to determine the disease allele.…”