40. SIMULTANEOUS PREIMPLANTATION GENETIC TESTING (PGT) FOR 5 DIFFERENT GENETIC CONDITIONS

readers we designed the project «Many men, many minds». Materials & Methods: We compared the experts’ interpretation with some arbitrary reference. The references are the clinical reports, created in Genetico Laboratory, based on the joined decision after discussion of program data between the clinical geneticist, laboratory geneticist and biologist. Participants of the study were 10 readers, 2 of which are outside Russia. We included 50 samples analyzed by aCGH (Cytochip 24sure, Illumina) and 50 samples analyzed by NGS (Veriseq, Illumina) in our project. The samples for interpretation were not representative of routine samples of Genetico Laboratory (not "typical" samples were chosen for interpretation, but rather most "hard to read" ones). The experts received data which include chromosome profiles, QC metrics, and chromosome imbalances which automatically determined by the BlueFuse Multi program (Illumina). We asked experts to provide an answer containing molecular karyotype for each sample and clinical recommendations for embryo transfer. Results: Interpretation of PGT-A results depends of expert's “school of thought” – at the same lab opinions tend to be more concordant. And interpretation of chromosome profiles by another expert can lead to a change in the clinical fate of the embryo. It is advisable to discuss PGT-A results between specialists before clinical report making. Interpretation of "hard to read" data of PGT-A is difficult and the role of the human factor very big. The “low specificity” of an expert may led to samples being recognized as aneuploid, although another expert using the same data will give an estimate of “norm” (or vice versa). Reanalysis of PGT-A data may lead to significant changes in clinical decisions

RBMO VOLUME 39 ISSUE s1 2019

regarding the fate of embryos. And after several months we tested if one interpreter could have two different opinions regarding the same sample. The participants of this additional experiment became 5 experts from initial list of participants. We asked them about the interpretation of 10 samples from the initial list. We did not reveal that these samples were same the experts interpreted several months before. We saw that the same expert may have different opinions on the same sample. Conclusions: PGT-A allows to increase IVF efficiency, however, we have room for improvement. It is possible to work on improving the process of data interpretation. Keywords: PGT-A; data interpretation; IVF efficiency

doi: 10.1016/j.rbmo.2019.04.092

40. SIMULTANEOUS PREIMPLANTATION GENETIC TESTING (PGT) FOR 5 DIFFERENT GENETIC CONDITIONS

M. Prokhorovich, S. Rechitsky, T. Pakhalchuk, G. San Ramon, R. Gershman, E. Bond, A. Kuliev Reproductive Genetic Innovations, Northbrook, United States

Introduction: It is a common practice to perform PGT-M for one or two disorders at the same test, but it is the first PGT performed simultaneously for 5 different conditions, which is presented below. Material and Methods: Consanguineous couple presented for PGT-M to avoid the risk of producing another affected child homozygous for four different autosomal recessive conditions identified in their previous offspring, including: (1) early infantile epileptic encephalopathy 5 (EIEE5), caused by SPTAN1 mutation; (2) xeroderma pigmentosum-complementation group C (XPG), caused by ERCC5

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mutation; (3) congenital merosin– deficient muscular dystrophy 1A (MDC1A), caused by LAMA2 mutation; and (4) phenylketonuria (PKU) caused by PAH mutation. As parents requested also aneuploiidy testing, PGT design was to combine PGT-A and PGT-M, involving mutation and linked marker testing by multiplex nested PCR, to avoid the undetected ADO of each of the genes tested. Results: Overall, 12 of 16 embryos reaching the blatocyst stage were tested together with NGS for PGT-A, of which 10 were affected, including 6 affected by one mutation, and four by two mutations. Only 2 embryos were unaffected carriers of all 4 gene mutations, of which one was with trisomy 13, so only a single embryos euploid and carrier of all 4 gene mutations was transferred, resulting, resulting in birth of a healthy unaffected baby. Although a cumulative risk of couple for producing an offspring affected by all the four conditions is only 0.4%, the couple still has been very unfortunate to produce such a child in their natural cycle. Although the chance for detecting unaffected embryo was also not high enough (31.6%), especially by added 50% risk for aneuploidy (15.8%), still one of 12 embryos tested was both euploid and normal carrier of all the mutations, resulting in a healthy, unaffected child. Conclusions: This is the world's first PGT for 5 different genetic conditions (EIEE5, XPG, MDC1A, PKU and aneuploidy) in a single test, resulting in a transfer of euploid embryo free of all the conditions tested, demonstrating feasibility and accuracy of simultaneous combined PGT for multiple genetic conditions. Keywords: PGT-M; Multiplex Nested PCR; Simultaneous PGT-M and PGT-A

doi: 10.1016/j.rbmo.2019.04.093