58. PGD-SEQ: VALIDATION OF A NOVEL SOLUTION FOR PGT-M AND PGT-SR BASED ON TARGET ENRICHMENT

Introduction Recently, we have developed PGD-Seq, which is a solution for PGT-M and PGT-SR analysis, which can be coupled to PGT-A. PGD-Seq has several advantages over other solutions: (1) PGD-Seq is designed to work widespread in any family from any ethnicity, so no specific customization is needed; (2) the same solution can be used to detect embryos with balanced translocations; (3) it is possible to detect even small unbalanced translocations, increasing the resolution of standard PGT-SR; (4) it can be combined with PGT-A in the same run and (5) it is an easy workflow with possibilty of automation. Here we present data about the performance of PGD-Seq in challenging situations. Material and methods Close to 200 cases of PGT-M and PGT-SR have been analyzed with PGD-Seq solution. Each PGD-Seq panel has been designed for a specific gene or region with a complex algorithm in order to select informative SNPs among different ethnicities. Finally, each panel involves around 200 pre-selected SNPs. Informativity study and embryo analysis have been done by PGD-Seq simultaneously in some cases. Frequently, PGD-Seq was combined with PGT-A. Results Up to know, more than 150 gene analysis and 200 case studies have been developed with PGD-Seq. Among different cases, some of them were very challenging. Firstly, the same panel was used in different ethnicities. Moreover, it was used in some couples with high level of consanguinity, where we were even able to identify informative SNPs. Due to the high density of SNPs in the regions studied, we were able to identify recombinant embryos in few different cases. Finally, due to the ability of combining direct and indirect testing, PGD-Seq was used in cases without any family member available in order to complete the informativity test, or with complex family combinations. Regarding to PGT-SR, the solution was able to differentiate normal from balanced embryos in several cases. Nowadays, FISH is commonly used in several labs for specific case studies, especially in those with a small portion of the chromosome affected. However, just with PGD-Seq, we were able to identify those small aberrations. Finally, the solution was used even in a case with an inversion. Conclusions The used of PGD-Seq shows its robustness in very challenging situations, without any previous setup. Additionally, the target approach instead of whole genome one keeps the costs of the test low enough to make it affordable for most of the couples.