False positive rate of an arrayCGH platform for single-cell preimplantation genetic screening and subsequent clinical application on day-3

Abstract

In this work, false positive rate of an arrayCGH platform for its use in day-3 single-blastomere analysis was calculated. For this purpose, 38 embryos diagnosed as abnormal on day-3 by FISH were re-biopsied on day-4. Single-cell day-4 arrayCGH diagnosis was then performed. A successful amplification was obtained in 97.4 % (37/38) of the day-4 cells analysed by arrayCGH. Day-3 FISH and day-4 arrayCGH diagnosis were concordant in 35/37 cases. The two discordant embryos were spread and all the cells from each embryo were re-analysed by FISH on day 5. The same error rate (2.7 %) for day-3 FISH and day-4 arrayCGH was obtained when comparing day-5 FISH re-analysis. After this pre-clinical phase, the platform was used for day-3 arrayCGH clinical application in 320 patients (1,760 embryos). Day-3 amplification rate was 98.6 %. An optimal reproductive outcome was obtained when applying arrayCGH to a clinical program: clinical pregnancy rate per cycle of 38.4 % and 60.3 % per transference were obtained, with an implantation rate of 53.5 %. Overall miscarriage rate was 10.6 %. Additionally, day-5 FISH re-analysis was performed in 42 of the embryos from the clinical phase, obtaining a concordance rate of 97.6 % with day-3 arrayCGH.

Comparison of array comparative genomic hybridization and quantitative real-time PCR-based aneuploidy screening of blastocyst biopsies

“…2,3 In contrast, aCGH CCS has not published preclinical accuracy using single cells isolated from cell lines with previously established karyotypes or blastomeres from embryos with prior validated CCS diagnoses. Instead, studies claiming validation of aCGH have used concordance with FISH, 13,14 despite the fact that FISH-based technology has failed to demonstrate clinical validity in multiple RCTs. 15 A recent RCT of aCGH indicated improved clinical efficacy in good-prognosis patients.…”

New Tools for Embryo Selection: Comprehensive Chromosome Screening by Array Comparative Genomic Hybridization

“…In our program, we first validated the aCGH platform in single cells from embryos previously diagnosed as abnormal by FISH, obtaining similar error rates below three percent for both techniques [36]. Next, we confirmed that there were no differences in efficiency and accuracy when comparing day-3 and day-5 whole embryo array analysis [30].…”

PGD for a carrier of an intrachromosomal insertion using aCGH

“…It is also less expensive and faster than the combined use of several molecular cytogenetic methods to identify unbalanced chromosomal rearrangements [Aboura et al 2002]. Array CGH on blastomeres typically provides results in approximately 97-98% of cases with an accuracy for aneuploidy of 97-98% [Gutierrez-Mateo et al 2011;Mir et al 2013]. Overall, PGD using aCGH is an appropriate reproductive option for carriers of chromosomal rearrangements, in general, and intrachromosomal insertions, in particular, due to the high risk of unbalanced meiotic recombination.…”