Talk:Preimplantation Genetic Screening
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Cite this page: Hill, M.A. (2024, April 19) Embryology Preimplantation Genetic Screening. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Talk:Preimplantation_Genetic_Screening |
2015
The Influence of Single Nucleotide Polymorphism Microarray-Based Molecular Karyotype on Preimplantation Embryonic Development Potential
PLoS One. 2015 Sep 18;10(9):e0138234. doi: 10.1371/journal.pone.0138234. eCollection 2015.
Li G1, He N1, Jin H1, Liu Y1, Guo Y1, Su Y1, Sun Y1.
Abstract
In order to investigate the influence of the molecular karyotype based on single nucleotide polymorphism (SNP) microarray on embryonic development potential in preimplantation genetic diagnosis (PGD), we retrospectively analyzed the clinical data generated by PGD using embryos retrieved from parents with chromosome rearrangements in our center. In total, 929 embryos from 119 couples had exact diagnosis and development status. The blastocyst formation rate of balanced molecular karyotype embryos was 56.6% (276/488), which was significantly higher than that of genetic imbalanced embryos 24.5% (108/441) (P<0.001). No significant difference was detected in blastocyst formation rates in the groups of maternal age<30, 30-35 and >35 respectively. Blastocyst formation rates of male and female embryos were 44.5% (183/411) and 38.8% (201/518) respectively, with no significant difference between them (P>0.05). The rates of balanced molecular karyotype embryos vary from groups of embryos with different cell numbers at 68 hours after insemination. The blastocyst formation rate of embryos with 6-8 cells (48.1%) was significantly higher than that of embryos with <6 cells (23.9%) and with >8 cells (42.9%) (P<0.05). As for the unbalanced embryos, there was no significant difference of the distribution of abnormal molecular karyotypes in the subgroup of the arrest, morula and blastocyst. Thus, we conclude that embryos with balanced molecular karyotype have significant higher development potential than those with imbalanced molecular karyotype whilst maternal age, embryo gender and types of abnormal molecular karyotype have no significant influence on blastocyst formation. Compared with embryos with <6 and >8 cells, embryos with 6-8 blastomeres have higher rate of balanced molecular karyotype and blastocyst formation.
PMID 26381524
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0138234
2014
Preimplantation genetic screening (PGS) still in search of a clinical application: a systematic review
Reprod Biol Endocrinol. 2014 Mar 15;12:22. doi: 10.1186/1477-7827-12-22.
Gleicher N1, Kushnir VA, Barad DH.
Abstract
Only a few years ago the American Society of Assisted Reproductive Medicine (ASRM), the European Society for Human Reproduction and Embryology (ESHRE) and the British Fertility Society declared preimplantation genetic screening (PGS#1) ineffective in improving in vitro fertilization (IVF) pregnancy rates and in reducing miscarriage rates. A presumably upgraded form of the procedure (PGS#2) has recently been reintroduced, and is here assessed in a systematic review. PGS#2 in comparison to PGS#1 is characterized by: (i) trophectoderm biopsy on day 5/6 embryos in place of day-3 embryo biopsy; and (ii) fluorescence in-situ hybridization (FISH) of limited chromosome numbers is replaced by techniques, allowing aneuploidy assessments of all 24 chromosome pairs. Reviewing the literature, we were unable to identify properly conducted prospective clinical trials in which IVF outcomes were assessed based on "intent to treat". Whether PGS#2 improves IVF outcomes can, therefore, not be determined. Reassessments of data, alleged to support the efficacy of PGS#2, indeed, suggest the opposite. Like with PGS#1, the introduction of PGS#2 into unrestricted IVF practice again appears premature, and threatens to repeat the PGS#1 experience, when thousands of women experienced reductions in IVF pregnancy chances, while expecting improvements. PGS#2 is an unproven and still experimental procedure, which, until evidence suggests otherwise, should only be offered under study conditions, and with appropriate informed consents.
PMID 24628895
2011
Origins and rates of aneuploidy in human blastomeres
Fertil Steril. 2011 Dec 21. [Epub ahead of print]
Rabinowitz M, Ryan A, Gemelos G, Hill M, Baner J, Cinnioglu C, Banjevic M, Potter D, Petrov DA, Demko Z. Source Natera Inc., Redwood City, California; School of Engineering, Aeronautics and Astronautics. Abstract OBJECTIVE: To characterize chromosomal error types and parental origin of aneuploidy in cleavage-stage embryos using an informatics-based technique that enables the elucidation of aneuploidy-causing mechanisms. DESIGN: Analysis of blastomeres biopsied from cleavage-stage embryos for preimplantation genetic screening during IVF. SETTING: Laboratory. PATIENT(S): Couples undergoing IVF treatment. INTERVENTION(S): Two hundred seventy-four blastomeres were subjected to array-based genotyping and informatics-based techniques to characterize chromosomal error types and parental origin of aneuploidy across all 24 chromosomes. MAIN OUTCOME MEASURE(S): Chromosomal error types (monosomy vs. trisomy; mitotic vs. meiotic) and parental origin (maternal vs. paternal). RESULT(S): The rate of maternal meiotic trisomy rose significantly with age, whereas other types of trisomy showed no correlation with age. Trisomies were mostly maternal in origin, whereas paternal and maternal monosomies were roughly equal in frequency. No examples of paternal meiotic trisomy were observed. Segmental error rates were found to be independent of maternal age.
CONCLUSION(S): All types of aneuploidy that rose with increasing maternal age can be attributed to disjunction errors during meiosis of the oocyte. Chromosome gains were predominantly maternal in origin and occurred during meiosis, whereas chromosome losses were not biased in terms of parental origin of the chromosome. The ability to determine the parental origin for each chromosome, as well as being able to detect whether multiple homologs from a single parent were present, allowed greater insights into the origin of aneuploidy. Copyright © 2012 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.
PMID 22195772
Preimplantation genetic diagnosis for inherited breast cancer: first clinical application and live birth in Spain
Fam Cancer. 2011 Dec 18. [Epub ahead of print]
Ramón Y Cajal T, Polo A, Martínez O, Giménez C, Arjona C, Llort G, Bassas L, Viscasillas P, Calaf J. Source Medical Oncology Department, Sant Pau Hospital, Barcelona, Spain, tramon@santpau.cat.
Abstract
Carriers of a mutation in BRCA1/2 genes confront a high lifetime risk of breast and ovarian cancer and fifty percent probability of passing the mutation to their offspring. Current options for risk management influence childbearing decisions. The indications for preimplantation genetic diagnosis (PGD) have now been expanded to include predisposition for single-gene, late-onset cancer but few cases have been reported to date despite the favorable opinion among professionals and carriers. A 28-year-old BRCA1 mutation carrier (5273G>A in exon 19) with a strong maternal history of breast cancer and 2 years of infertility decided to pursue PGD to have a healthy descendent after an accurate assessment of her reproductive options. The procedure was approved by the national regulation authority and a PGD cycle was initiated. Four out of 6 embryos harbored the mutation. The two unaffected embryos were implanted in the uterus. A singleton pregnancy was achieved and a male baby was delivered at term. Consented umbilical cord blood testing confirmed the accuracy of the technique. Individualized PGD for inherited breast predisposition is feasible in the context of a multidisciplinary team.
PMID 22179695
The genetic screening of preimplantation embryos by comparative genomic hybridisation
Reprod Biol. 2011 Dec;11 Suppl 3:51-60.
Traversa MV, Marshall J, McArthur S, Leigh D. Source Genea, Level 2, 321 Kent Street, Sydney NSW 2000, Australia; e-mail: maria.traversa@genea.com.au.
Abstract
Comparative genomic hybridization (CGH) is an indirect DNA-based test which allows for the accurate analysis of aneuploidy involving any of the 24 types of chromosomes present (22 autosomes and the X and Y sex chromosomes). Traditionally, embryos have been screened using fluorescence in situ hybridization (FISH) - a technique that was limited in the number of chromosomes able to be identified in any one sample. Early CGH reports on aneuploidy in preimplantation embryos showed that any of the 24 chromosomes could be involved and so FISH methods were going to be ineffective in screening out abnormal embryos. Our results from routine clinical application of array CGH in preimplantation genetic diagnosis (PGD) patients confirm previous reports on patterns of chromosomal contribution to aneuploidy. The pregnancy outcomes following embryo transfer also indicate that despite the requirement to freeze embryos, rates are encouraging, and successful ongoing pregnancies can be achieved.
PMID 22200879
Preimplantation genetic screening: does it help or hinder IVF treatment and what is the role of the embryo?
J Assist Reprod Genet. 2011 Sep;28(9):833-49. Epub 2011 Jul 9.
Ly KD, Agarwal A, Nagy ZP. Source Center for Reproductive Medicine, Cleveland Clinic, Cleveland, Ohio, USA. kimdaoly@yahoo.com
Abstract
Despite an ongoing debate over its efficacy, preimplantation genetic screening (PGS) is increasingly being used to detect numerical chromosomal abnormalities in embryos to improve implantation rates after IVF. The main indications for the use of PGS in IVF treatments include advanced maternal age, repeated implantation failure, and recurrent pregnancy loss. The success of PGS is highly dependent on technical competence, embryo culture quality, and the presence of mosaicism in preimplantation embryos. Today, cleavage stage biopsy is the most commonly used method for screening preimplantation embryos for aneuploidy. However, blastocyst biopsy is rapidly becoming the more preferred method due to a decreased likelihood of mosaicism and an increase in the amount of DNA available for testing. Instead of using 9 to 12 chromosome FISH, a 24 chromosome detection by aCGH or SNP microarray will be used. Thus, it is advised that before attempting to perform PGS and expecting any benefit, extended embryo culture towards day 5/6 should be established and proven and the clinical staff should demonstrate competence with routine competency assessments. A properly designed randomized control trial is needed to test the potential benefits of these new developments.
PMID 21743973
2010
Preimplantation diagnosis of genetic diseases
J Postgrad Med. 2010 Oct-Dec;56(4):317-20.
Adiga SK, Kalthur G, Kumar P, Girisha KM. Source Division of Reproductive Medicine, Kasturba Medical College, Manipal University, Manipal, India.
Abstract
One of the landmarks in clinical genetics is prenatal diagnosis of genetic disorders. The recent advances in the field have made it possible to diagnose the genetic conditions in the embryos before implantation in a setting of in vitro fertilization. Polymerase chain reaction and fluorescence in situ hybridization are the two common techniques employed on a single or two cells obtained via embryo biopsy. The couple who seek in vitro fertilization may screen their embryos for aneuploidy and the couple at risk for a monogenic disorder but averse to abortion of the affected fetuses after prenatal diagnosis, are likely to be the best candidates to undergo this procedure. This article reviews the technique, indications, benefits, and limitations of pre-implantation genetic testing in clinical practice. PMID 20935409
The effects of different laser pulse lengths on the embryo biopsy procedure and embryo development to the blastocyst stage
J Assist Reprod Genet. 2010 Nov;27(11):663-7. Epub 2010 Aug 5.
Taylor TH, Gilchrist JW, Hallowell SV, Hanshew KK, Orris JJ, Glassner MJ, Wininger JD. Source Main Line Fertility and Reproductive Medicine, 130 S. Bryn Mawr Ave, Ground Floor, D Wing, Bryn Mawr, PA 19010, USA. taylort@mainlinefertility.com Abstract PURPOSE: a laser is commonly used to remove a blastomere from an embryo for genetic testing. The laser uses intense heat which could possibly disrupt embryo development. It is the goal of this study to test the effects of different laser pulse lengths (and consequently heat) on the embryo biopsy procedure and embryo development. METHODS: each embryo biopsy was performed randomly utilizing laser pulse lengths of 0.604mS (group I), 0.708mS (group II), and 1.010mS (group III). RESULTS: for groups I, II, and III, 83, 86, and 71 embryos were biopsied, respectively. There was no difference in day 5 embryo quality or lysed blastomeres between groups. Average number of blastomeres biopsied between group I (1.0 ± 0.0), II (1.0 ± 0.2), and III (1.1 ± 0.2) was significant (0.0001). CONCLUSION: our data demonstrates that laser pulse length does not influence the embryo biopsy procedure or embryo development.
PMID 20686919
