Abstract
A previous study comparing the performance of different platforms for DNA microarray found that the oligonucleotide (oligo) microarray platform containing 385K isothermal probes had the best performance when evaluating dosage sensitivity, precision, specificity, sensitivity and copy number variations border definition. Although oligo microarray platform has been used in some research fields and clinics, it has not been used for aneuploidy screening in human embryos. The present study was designed to use this new microarray platform for preimplantation genetic screening in the human. A total of 383 blastocysts from 72 infertility patients with either advanced maternal age or with previous miscarriage were analyzed after biopsy and microarray. Euploid blastocysts were transferred to patients and clinical pregnancy and implantation rates were measured. Chromosomes in some aneuploid blastocysts were further analyzed by fluorescence in-situ hybridization (FISH) to evaluate accuracy of the results. We found that most (58.1%) of the blastocysts had chromosomal abnormalities that included single or multiple gains and/or losses of chromosome(s), partial chromosome deletions and/or duplications in both euploid and aneuploid embryos. Transfer of normal euploid blastocysts in 34 cycles resulted in 58.8% clinical pregnancy and 54.4% implantation rates. Examination of abnormal blastocysts by FISH showed that all embryos had matching results comparing microarray and FISH analysis. The present study indicates that oligo microarray conducted with a higher resolution and a greater number of probes is able to detect not only aneuploidy, but also minor chromosomal abnormalities, such as partial chromosome deletion and/or duplication in human embryos. Preimplantation genetic screening of the aneuploidy by DNA microarray is an advanced technology used to select embryos for transfer and improved embryo implantation can be obtained after transfer of the screened normal embryos.
Highlights
Aneuploidy is one of the most crucial factors affecting embryo implantation and is a major cause of birth defects [1], [2]
When samples with known lengths of chromosomal abnormalities (7q11, 2q12 and 17q24) were labeled with higher resolution oligo chips, we found that the segments that the NimbleGen oligo microarray could detect were 1.3 and 1.6 mb
The NimbleGen 630K chip can detect segments as small as 1.3 mb (Figure 2), while bacterial artificial chromosomes (BAC) 32K array can detect segments of 4 mb, indicating that the NimbleGen oligo array platform is more sensitive than the BAC array platform
Summary
Aneuploidy is one of the most crucial factors affecting embryo implantation and is a major cause of birth defects [1], [2]. It has been reported that the aneuploidy rate is extremely high in patients with repeated implantation failure [3], recurrent miscarriages [4], previous aneuploid conceptions [5] and advanced maternal age [2], [6,7,8,9]. It has been found that a high aneuploidy rate (,40%) is present in younger (,31 yrs old) patients undergoing in vitro fertilization (IVF) [10], [11]. Two major microarray platforms are used for PGS in human IVF.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
