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Session


Keywords: Infertility; Genetic testing; Genomics; Prenatal diagnosis; Aneuploidy

Authors:
J. Dattani 1; S. Chettiar 2; A. Patel 2; D. Jhala 3; B. Dey 4; C. Dey 1; U. Radhakrishna 5

Affiliations:
1) RoHFW, Ministry of Health and Family Welfare, Ahmedabad, Gujarat, India; 2) Genexplore Diagnostics and Research Centre, Ahmedabad, Gujarat; 3) Department of Zoology, Gujarat University, Ahmedabad; 4) Shri D M Patil Medical College, Vijayapura, Karanataka, Inidia; 5) Departmetn of Obstetrics and Gynaecology, William Beaumont School of Medicine, Detroit, USA


Introduction: Assisted reproductive technology (ART) techniques have become common practice in many countries today and has supported numerous infertile couples worldwide. Although, ART has evolved technologically in last few years resulting in increased success rate and low cost. Of all aspects of ART viz, gamete retrieval, in vitro fertilization, selection of embryo, cryopreservation, vitrification and embryo transfer, selection of embryo has significant impact on ART outcome. Advance genomic technologies like next generation sequencing and microarray can aid clinicians in selecting embryos with normal euploid and genomic content. Here, we present our experience with 1200 embryos from 280 females.
Material and Method: Subjects included in the study were both women and men who were then sub-grouped based on four major reasons viz. 1) advanced maternal age, 2) more than three IVF failures, 3) low sperm count and 4) genetic indications. Blastomere or Trophectoderm biopsy were performed in 1200 embryos from 280 females undergoing IVF treatment. These single cell (blastomere) or four to six cells (trophectoderm) biopsy were subjected to whole genome amplification (WGA) using a picoplex WGA kit (Takara). Amplified product was then taken up for customized microarray and NGS based chromosomal aneuploidy analysis where a lower mark of 10MB of deletion duplication was taken for reporting and a mosacisim of minimum 25% was reported.
Results: Combined NGS and microarray data revealed 272 (22.66%) embryo had segmental or whole chromosomal aneuploidy. From the pooled data of all aneuploid embryos, it is evident that chromosome 16 was involved in 4.33% of events and chromosome 8 showed the least (1.26%) incidence of deletion and duplication. Among the incidence of aneuploidy heterozygous deletion was a significantly frequent (18.7%) event as compared to homozygous deletion (8.42%), homozygous duplication (9.65%) and heterozygous duplication (12.4%).
Conclusion: A significant number of embryos showed chromosomal and/or segmental aneuploidy, thus requiring the genetic screening of potential embryos in couples undergoing IVF treatment. Chromosome 16 has maximum risk of deletion or duplication as compared to other chromosomes.