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Otago039404
This document summarizes a presentation on preimplantation genetic diagnosis (PGD) in New Zealand. PGD combines IVF with genetic testing of embryos to screen for inherited disorders and conditions. It is currently regulated under New Zealand law and allowed only to select embryos without serious genetic disorders or diseases. The presentation outlines the science of PGD, its potential uses and limitations, ethical concerns around disability, embryo status, and playing God. It also reviews New Zealand's legal framework for PGD, which prohibits sex selection but allows PGD for established medical reasons through a regulatory body. There is discussion on further developing the legal guidelines regarding what conditions should be eligible for PGD screening.
Dr. irene souter pgd stickler foundation (2)
This document discusses preimplantation genetic diagnosis (PGD), which involves biopsy of a single cell from each embryo followed by genetic analysis to identify normal embryos for implantation. PGD is offered to couples at risk of passing on genetic disorders, chromosomal issues, or with recurrent pregnancy loss. The process involves ovarian stimulation, egg retrieval, fertilization, embryo biopsy on day 3, genetic analysis, and embryo transfer. Common indications for PGD include single gene disorders, translocations, aneuploidy screening, and HLA matching. While mistakes can occur, studies show delivery outcomes and malformation rates are similar to ICSI. PGD has allowed many to have healthy children who would otherwise be at high risk of genetic conditions.
Dukengineer2012
This document is the 2011-2012 issue of the DukEngineer Magazine from the Edmund T. Pratt Jr. School of Engineering at Duke University. It contains articles on various engineering research projects, student experiences, alumni profiles and updates on the Pratt School. The Dean provides a letter highlighting the growth and momentum at Pratt, including increased research expenditures, new degree programs, and opportunities for students.
Embryotransferincattle (3)
Embryo transfer involves removing embryos from female cattle of superior genetics and implanting them into recipient females. This allows one donor cow to produce many offspring, improving herd genetics faster. The process is complicated, requiring synchronization of donor and recipient estrous cycles and supervision by trained professionals. While expensive, embryo transfer can boost milk and weight production if used with genetically superior cattle.
pgs Journal.pgen.1003025
1) The study analyzed over 10,000 chromosomes in embryos and oocytes from 44 patients carrying Robertsonian translocations and over 200,000 chromosomes in control samples to conclusively determine if an inter-chromosomal effect (ICE) exists.
2) The results showed a highly significant increase in abnormal segregation of structurally normal chromosomes in embryos, but not oocytes, of female carriers, indicating a mitotic rather than meiotic origin of the ICE.
3) The findings have implications for understanding genetic stability during early human development and are clinically relevant for patients carrying Robertsonian translocations.
Recommended
Otago039404
This document summarizes a presentation on preimplantation genetic diagnosis (PGD) in New Zealand. PGD combines IVF with genetic testing of embryos to screen for inherited disorders and conditions. It is currently regulated under New Zealand law and allowed only to select embryos without serious genetic disorders or diseases. The presentation outlines the science of PGD, its potential uses and limitations, ethical concerns around disability, embryo status, and playing God. It also reviews New Zealand's legal framework for PGD, which prohibits sex selection but allows PGD for established medical reasons through a regulatory body. There is discussion on further developing the legal guidelines regarding what conditions should be eligible for PGD screening.
Dr. irene souter pgd stickler foundation (2)
This document discusses preimplantation genetic diagnosis (PGD), which involves biopsy of a single cell from each embryo followed by genetic analysis to identify normal embryos for implantation. PGD is offered to couples at risk of passing on genetic disorders, chromosomal issues, or with recurrent pregnancy loss. The process involves ovarian stimulation, egg retrieval, fertilization, embryo biopsy on day 3, genetic analysis, and embryo transfer. Common indications for PGD include single gene disorders, translocations, aneuploidy screening, and HLA matching. While mistakes can occur, studies show delivery outcomes and malformation rates are similar to ICSI. PGD has allowed many to have healthy children who would otherwise be at high risk of genetic conditions.
Dukengineer2012
This document is the 2011-2012 issue of the DukEngineer Magazine from the Edmund T. Pratt Jr. School of Engineering at Duke University. It contains articles on various engineering research projects, student experiences, alumni profiles and updates on the Pratt School. The Dean provides a letter highlighting the growth and momentum at Pratt, including increased research expenditures, new degree programs, and opportunities for students.
Embryotransferincattle (3)
Embryo transfer involves removing embryos from female cattle of superior genetics and implanting them into recipient females. This allows one donor cow to produce many offspring, improving herd genetics faster. The process is complicated, requiring synchronization of donor and recipient estrous cycles and supervision by trained professionals. While expensive, embryo transfer can boost milk and weight production if used with genetically superior cattle.
pgs Journal.pgen.1003025
1) The study analyzed over 10,000 chromosomes in embryos and oocytes from 44 patients carrying Robertsonian translocations and over 200,000 chromosomes in control samples to conclusively determine if an inter-chromosomal effect (ICE) exists.
2) The results showed a highly significant increase in abnormal segregation of structurally normal chromosomes in embryos, but not oocytes, of female carriers, indicating a mitotic rather than meiotic origin of the ICE.
3) The findings have implications for understanding genetic stability during early human development and are clinically relevant for patients carrying Robertsonian translocations.
1 s2.0-s1472648313005798-main
This study investigated the incidence and clinical implications of multinucleated (MN) blastomeres in embryos undergoing preimplantation genetic screening (PGS) or preimplantation genetic diagnosis (PGD). The study found that 41.3% of cycles involved at least one MN embryo. While the majority of MN blastomeres showed chromosomal abnormalities, some embryos with MN blastomeres free of genetic abnormalities tested resulted in three healthy deliveries. This suggests that genetic analysis of MN embryos can identify some that may result in healthy births.
Ecas1 1410
- Dr. Chang informs 37-year-old patient Niki about declining fertility with age and recommends an AMH test to evaluate her ovarian reserve since Niki wants to have children.
- Niki's test results show very low AMH levels. Dr. Goldstein, who is covering for Dr. Chang, is upset that Dr. Chang informed Niki without considering her lack of a partner and career focus.
- The commentary argues that physicians have a responsibility to provide patients information relevant to their reproductive goals and futures to allow for informed decision making, even if the news is unexpected or unwelcome.
Clinical manaement of in vitrofertilizatonwithpreimplantation geneticdiagnosi...
This document discusses clinical management of in vitro fertilization with preimplantation genetic diagnosis (PGD). It provides an overview of PGD and its indications. Key points discussed include that PGD seems generally safe when performed by experienced labs, children born from PGD have similar outcomes as regular IVF/ICSI children, and optimization of ovarian stimulation and embryo biopsy techniques can help maximize IVF-PGD success rates. Special challenges like nondisclosure PGD and PGD for HLA typing are also reviewed.
1 s2.0-s1472648313006366-main
The document compares euploidy rates between blastomere biopsies on day 3 embryos and trophectoderm biopsies on day 5-7 blastocysts. Of the 1603 embryos biopsied, 31% were euploid, 62% were aneuploid, and 7% were unanalyzable. A significantly higher proportion of embryos were euploid with trophectoderm biopsy on day 5-7 (42%) compared to blastomere biopsy on day 3 (24%). Combining blastocyst culture, trophectoderm biopsy, and aneuploidy screening using aCGH provides a more efficient means of achieving euploid pregnancies in IVF.
Fetal quant cuhk bioinformatics
This document describes a new statistical method called FetalQuant that can deduce the fractional fetal DNA concentration directly from massively parallel sequencing (MPS) data of DNA in maternal plasma, without requiring prior genotype information. FetalQuant implements a binomial mixture model to estimate the fractional fetal DNA concentration by maximum likelihood using only the allelic count data from targeted MPS. This allows improved determination of the fetal DNA fraction without additional laboratory steps. The authors believe FetalQuant can help expand the applications of MPS-based non-invasive prenatal diagnosis.
Mu
This document discusses preimplantation genetic screening (PGS) with fresh embryo transfer. It provides an overview of PGS using comprehensive chromosome analysis (CCA) with blastocyst biopsy and either fresh day 5 or 6 embryo transfer or frozen embryo transfer. Key advantages of blastocyst biopsy and CCA include improved implantation rates, elimination of the negative effect of maternal age on implantation, and the ability to perform embryo banking which facilitates multiple cycles for patients with poor prognosis.
Preimplantation genetic diagnosis_oct_11
This document outlines a national medical policy on preimplantation genetic diagnosis (PGD) in assisted reproduction. It considers PGD medically necessary in certain situations to screen embryos for genetic disorders and conditions. PGD may be used to test for aneuploidy, single gene disorders, or repeated IVF failure. The policy lists specific criteria that must be met and details coverage guidelines. It also considers PGD investigational for some uses, such as non-medical gender selection or testing for adult-onset disorders.
pgs munne Pre genetic screen (1)
This document discusses preimplantation genetic screening (PGS) using comprehensive chromosome screening (CCS) techniques like array comparative genomic hybridization (aCGH) to test embryos for chromosome abnormalities. It provides data from over 39,000 PGS procedures performed by Reprogenetics Laboratories showing that CCS-based PGS can eliminate the negative impact of maternal age on implantation rates by selecting euploid embryos, with randomized controlled trials demonstrating significantly higher implantation and pregnancy rates for PGS compared to untested embryos. While the technique has a low error rate of around 2%, some embryos may be mosaic and not fully representative of the inner cell mass.
Shapiro
This document summarizes research comparing outcomes of fresh embryo transfers versus frozen embryo transfers (FET). Key points include:
- FET outcomes were found to equal or exceed fresh outcomes, suggesting endometrial asynchrony with fresh cycles due to ovarian stimulation effects.
- Slower developing day 6 blastocysts showed lower implantation rates than day 5 blastocysts with fresh but not FET transfers, again indicating endometrial asynchrony issues with fresh cycles.
- Studies directly comparing matched fresh and FET cycles found significantly higher pregnancy and implantation rates with FET, demonstrating cryopreservation can overcome negative endometrial effects of ovarian stimulation.
Fresh or frozen embryos – which are better
This document summarizes research comparing outcomes of fresh embryo transfers versus frozen embryo transfers (FET). It finds that FET results in better pregnancy and implantation rates than fresh transfers, likely due to ovarian stimulation negatively impacting endometrial receptivity in fresh cycles. Specifically, FET cycles have higher success rates for slower developing embryos and embryos transferred in cycles with premature progesterone elevation. FET outcomes in young patients can rival fresh donor egg cycles. Randomized trials show significantly higher pregnancy rates with FET compared to fresh transfer in normal responders.
1 s2.0-s0929664613000958-main
This study evaluated the use of blastocyst biopsy and array comparative genomic hybridization (aCGH) for preimplantation genetic diagnosis in 12 patients with chromosomal translocations. The diagnostic efficiency was 90.2% and euploidy rate was 32.7%. Ten cycles of thawed embryo transfer resulted in three live births and three ongoing pregnancies, for an ongoing pregnancy rate of 60% per transfer cycle. Prenatal diagnoses confirmed the PGD/aCGH results. The strategy demonstrates promising outcomes and may provide a more effective approach than traditional methods like fluorescence in situ hybridization. Larger studies are still needed to verify the results.
1 s2.0-s1472648313006354-main
This study analyzed aneuploidy rates, apoptotic markers, and DNA fragmentation in sperm samples from normozoospermic men with unexplained infertility. Samples underwent density gradient centrifugation and then magnetic activated cell sorting (MACS). MACS significantly reduced the percentage of aneuploid, apoptotic, and DNA-damaged sperm. A positive correlation was found between reduced aneuploidy and lower DNA damage after MACS, but no correlation with apoptotic markers. The interactions between apoptotic markers, DNA integrity, and aneuploidy, as well as the effects of MACS on these parameters, require further investigation.
Fetal fraction nipt pnd
This document discusses the impact of fetal fraction, the percentage of cell-free DNA in maternal plasma that is of fetal origin, on the performance of next generation sequencing tests for detecting common fetal aneuploidies such as Down syndrome. It finds that test performance is better with higher fetal fractions. Specifically, the distribution of test results for Down syndrome pregnancies improves and separates more from normal pregnancies as fetal fraction increases. Additionally, false negative rates and rates of low fetal fractions are highest for women with high maternal weights. When a fetus has mosaicism for a trisomy, the degree of mosaicism affects the effective fetal fraction and thus impacts test performance.
Gb 2011-12-9-228
This document discusses how exome sequencing is revolutionizing the identification of genes that cause Mendelian diseases. It provides three main points:
1) Exome sequencing has identified over 30 new disease genes since 2009, improving clinical diagnosis, genotype-phenotype correlations, and understanding of rare genetic variation.
2) Our view of Mendelian diseases is changing as exome sequencing is less biased than previous methods and is identifying disease genes in cases where the genetic cause was unclear.
3) Exome sequencing is now the primary tool for studying Mendelian diseases as it can sequence hundreds of patient exomes per year more efficiently than whole genome sequencing.
Pone.0034901
1) Genome-wide gene expression analysis identified immune response and lymphangiogenesis pathways as implicated in the pathogenesis of fetal chylothorax (FC). Genes involved in immune response were universally up-regulated, while genes related to lymphangiogenesis were down-regulated in fetal pleural fluids of FC cases.
2) Expression of the ITGA9 gene, which is important for lymphangiogenesis, was concordant with trends in the lymphangiogenesis pathway. ITGA9 mutations have previously been associated with FC.
3) For one fetus (Ind) carrying an ITGA9 mutation, immune response pathways decreased after successful treatment of FC with OK-432 pleurodesis, while lymphangiogenesis pathways
Mat weight ga fetal frac nipt pnd
- The study analyzed 22,384 maternal plasma samples to determine the effects of gestational age and maternal weight on the percentage of fetal cell-free DNA (cfDNA) in maternal plasma.
- They found that the percentage of fetal cfDNA increases with gestational age, rising 0.1% per week between 10-21 weeks and 1% per week after 21 weeks. Fetal cfDNA percentage decreases with increasing maternal weight.
- Of samples that were redrawn due to initially low fetal cfDNA, 56% of second draws had over 4% fetal cfDNA, showing that fetal percentage often improves with redraws, especially at later gestational ages.
Snp nipt pnd
This method accurately detected sex chromosome aneuploidies (45,X, 47,XXY, 47,XYY) in cell-free DNA isolated from maternal plasma. It analyzed 201 pregnancies including 16 with sex chromosome aneuploidies and 185 normal controls. The method involved massively multiplexed PCR and sequencing of 19,488 SNPs across chromosomes 13, 18, 21, X and Y. Using a statistical algorithm to analyze the SNP data, it correctly identified the copy number at all five chromosomes in 93% of samples, detecting sex chromosome aneuploidies with high sensitivity and specificity.
Nihms379831 stephen quake
This document describes a new noninvasive method for sequencing the entire fetal genome using cell-free DNA found in a pregnant woman's blood. The method works by counting parental haplotypes - combinations of maternal and paternal chromosomes passed to the fetus. Since a small percentage of cell-free DNA comes from the fetus, haplotypes inherited by the fetus can be identified by which have a higher count. Researchers tested this method on two pregnancies and were able to determine the fetal genomes without any invasive procedures. This noninvasive prenatal testing could allow comprehensive screening for genetic diseases.
Twin zygosity nipt
This document describes a study that used massively parallel sequencing of cell-free DNA in maternal blood to assess zygosity and detect fetal aneuploidies in twin pregnancies. The study determined zygosity by analyzing apparent fractional fetal DNA concentrations across genomic regions. It then calculated individual fetal DNA concentrations for dizygotic twins to assess each fetus. The study detected trisomy 21 in one twin and trisomy 18 in the other twin of two pregnancies. It demonstrated that noninvasive prenatal testing for aneuploidies can be achieved for twin pregnancies using this method.
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1 s2.0-s1472648313005798-main
This study investigated the incidence and clinical implications of multinucleated (MN) blastomeres in embryos undergoing preimplantation genetic screening (PGS) or preimplantation genetic diagnosis (PGD). The study found that 41.3% of cycles involved at least one MN embryo. While the majority of MN blastomeres showed chromosomal abnormalities, some embryos with MN blastomeres free of genetic abnormalities tested resulted in three healthy deliveries. This suggests that genetic analysis of MN embryos can identify some that may result in healthy births.
Ecas1 1410
- Dr. Chang informs 37-year-old patient Niki about declining fertility with age and recommends an AMH test to evaluate her ovarian reserve since Niki wants to have children.
- Niki's test results show very low AMH levels. Dr. Goldstein, who is covering for Dr. Chang, is upset that Dr. Chang informed Niki without considering her lack of a partner and career focus.
- The commentary argues that physicians have a responsibility to provide patients information relevant to their reproductive goals and futures to allow for informed decision making, even if the news is unexpected or unwelcome.
Clinical manaement of in vitrofertilizatonwithpreimplantation geneticdiagnosi...
This document discusses clinical management of in vitro fertilization with preimplantation genetic diagnosis (PGD). It provides an overview of PGD and its indications. Key points discussed include that PGD seems generally safe when performed by experienced labs, children born from PGD have similar outcomes as regular IVF/ICSI children, and optimization of ovarian stimulation and embryo biopsy techniques can help maximize IVF-PGD success rates. Special challenges like nondisclosure PGD and PGD for HLA typing are also reviewed.
1 s2.0-s1472648313006366-main
The document compares euploidy rates between blastomere biopsies on day 3 embryos and trophectoderm biopsies on day 5-7 blastocysts. Of the 1603 embryos biopsied, 31% were euploid, 62% were aneuploid, and 7% were unanalyzable. A significantly higher proportion of embryos were euploid with trophectoderm biopsy on day 5-7 (42%) compared to blastomere biopsy on day 3 (24%). Combining blastocyst culture, trophectoderm biopsy, and aneuploidy screening using aCGH provides a more efficient means of achieving euploid pregnancies in IVF.
Fetal quant cuhk bioinformatics
This document describes a new statistical method called FetalQuant that can deduce the fractional fetal DNA concentration directly from massively parallel sequencing (MPS) data of DNA in maternal plasma, without requiring prior genotype information. FetalQuant implements a binomial mixture model to estimate the fractional fetal DNA concentration by maximum likelihood using only the allelic count data from targeted MPS. This allows improved determination of the fetal DNA fraction without additional laboratory steps. The authors believe FetalQuant can help expand the applications of MPS-based non-invasive prenatal diagnosis.
Mu
This document discusses preimplantation genetic screening (PGS) with fresh embryo transfer. It provides an overview of PGS using comprehensive chromosome analysis (CCA) with blastocyst biopsy and either fresh day 5 or 6 embryo transfer or frozen embryo transfer. Key advantages of blastocyst biopsy and CCA include improved implantation rates, elimination of the negative effect of maternal age on implantation, and the ability to perform embryo banking which facilitates multiple cycles for patients with poor prognosis.
Preimplantation genetic diagnosis_oct_11
This document outlines a national medical policy on preimplantation genetic diagnosis (PGD) in assisted reproduction. It considers PGD medically necessary in certain situations to screen embryos for genetic disorders and conditions. PGD may be used to test for aneuploidy, single gene disorders, or repeated IVF failure. The policy lists specific criteria that must be met and details coverage guidelines. It also considers PGD investigational for some uses, such as non-medical gender selection or testing for adult-onset disorders.
pgs munne Pre genetic screen (1)
This document discusses preimplantation genetic screening (PGS) using comprehensive chromosome screening (CCS) techniques like array comparative genomic hybridization (aCGH) to test embryos for chromosome abnormalities. It provides data from over 39,000 PGS procedures performed by Reprogenetics Laboratories showing that CCS-based PGS can eliminate the negative impact of maternal age on implantation rates by selecting euploid embryos, with randomized controlled trials demonstrating significantly higher implantation and pregnancy rates for PGS compared to untested embryos. While the technique has a low error rate of around 2%, some embryos may be mosaic and not fully representative of the inner cell mass.
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Shapiro
This document summarizes research comparing outcomes of fresh embryo transfers versus frozen embryo transfers (FET). Key points include:
- FET outcomes were found to equal or exceed fresh outcomes, suggesting endometrial asynchrony with fresh cycles due to ovarian stimulation effects.
- Slower developing day 6 blastocysts showed lower implantation rates than day 5 blastocysts with fresh but not FET transfers, again indicating endometrial asynchrony issues with fresh cycles.
- Studies directly comparing matched fresh and FET cycles found significantly higher pregnancy and implantation rates with FET, demonstrating cryopreservation can overcome negative endometrial effects of ovarian stimulation.
Fresh or frozen embryos – which are better
This document summarizes research comparing outcomes of fresh embryo transfers versus frozen embryo transfers (FET). It finds that FET results in better pregnancy and implantation rates than fresh transfers, likely due to ovarian stimulation negatively impacting endometrial receptivity in fresh cycles. Specifically, FET cycles have higher success rates for slower developing embryos and embryos transferred in cycles with premature progesterone elevation. FET outcomes in young patients can rival fresh donor egg cycles. Randomized trials show significantly higher pregnancy rates with FET compared to fresh transfer in normal responders.
1 s2.0-s0929664613000958-main
This study evaluated the use of blastocyst biopsy and array comparative genomic hybridization (aCGH) for preimplantation genetic diagnosis in 12 patients with chromosomal translocations. The diagnostic efficiency was 90.2% and euploidy rate was 32.7%. Ten cycles of thawed embryo transfer resulted in three live births and three ongoing pregnancies, for an ongoing pregnancy rate of 60% per transfer cycle. Prenatal diagnoses confirmed the PGD/aCGH results. The strategy demonstrates promising outcomes and may provide a more effective approach than traditional methods like fluorescence in situ hybridization. Larger studies are still needed to verify the results.
1 s2.0-s1472648313006354-main
This study analyzed aneuploidy rates, apoptotic markers, and DNA fragmentation in sperm samples from normozoospermic men with unexplained infertility. Samples underwent density gradient centrifugation and then magnetic activated cell sorting (MACS). MACS significantly reduced the percentage of aneuploid, apoptotic, and DNA-damaged sperm. A positive correlation was found between reduced aneuploidy and lower DNA damage after MACS, but no correlation with apoptotic markers. The interactions between apoptotic markers, DNA integrity, and aneuploidy, as well as the effects of MACS on these parameters, require further investigation.
Fetal fraction nipt pnd
This document discusses the impact of fetal fraction, the percentage of cell-free DNA in maternal plasma that is of fetal origin, on the performance of next generation sequencing tests for detecting common fetal aneuploidies such as Down syndrome. It finds that test performance is better with higher fetal fractions. Specifically, the distribution of test results for Down syndrome pregnancies improves and separates more from normal pregnancies as fetal fraction increases. Additionally, false negative rates and rates of low fetal fractions are highest for women with high maternal weights. When a fetus has mosaicism for a trisomy, the degree of mosaicism affects the effective fetal fraction and thus impacts test performance.
Gb 2011-12-9-228
This document discusses how exome sequencing is revolutionizing the identification of genes that cause Mendelian diseases. It provides three main points:
1) Exome sequencing has identified over 30 new disease genes since 2009, improving clinical diagnosis, genotype-phenotype correlations, and understanding of rare genetic variation.
2) Our view of Mendelian diseases is changing as exome sequencing is less biased than previous methods and is identifying disease genes in cases where the genetic cause was unclear.
3) Exome sequencing is now the primary tool for studying Mendelian diseases as it can sequence hundreds of patient exomes per year more efficiently than whole genome sequencing.
Pone.0034901
1) Genome-wide gene expression analysis identified immune response and lymphangiogenesis pathways as implicated in the pathogenesis of fetal chylothorax (FC). Genes involved in immune response were universally up-regulated, while genes related to lymphangiogenesis were down-regulated in fetal pleural fluids of FC cases.
2) Expression of the ITGA9 gene, which is important for lymphangiogenesis, was concordant with trends in the lymphangiogenesis pathway. ITGA9 mutations have previously been associated with FC.
3) For one fetus (Ind) carrying an ITGA9 mutation, immune response pathways decreased after successful treatment of FC with OK-432 pleurodesis, while lymphangiogenesis pathways
Mat weight ga fetal frac nipt pnd
- The study analyzed 22,384 maternal plasma samples to determine the effects of gestational age and maternal weight on the percentage of fetal cell-free DNA (cfDNA) in maternal plasma.
- They found that the percentage of fetal cfDNA increases with gestational age, rising 0.1% per week between 10-21 weeks and 1% per week after 21 weeks. Fetal cfDNA percentage decreases with increasing maternal weight.
- Of samples that were redrawn due to initially low fetal cfDNA, 56% of second draws had over 4% fetal cfDNA, showing that fetal percentage often improves with redraws, especially at later gestational ages.
Snp nipt pnd
This method accurately detected sex chromosome aneuploidies (45,X, 47,XXY, 47,XYY) in cell-free DNA isolated from maternal plasma. It analyzed 201 pregnancies including 16 with sex chromosome aneuploidies and 185 normal controls. The method involved massively multiplexed PCR and sequencing of 19,488 SNPs across chromosomes 13, 18, 21, X and Y. Using a statistical algorithm to analyze the SNP data, it correctly identified the copy number at all five chromosomes in 93% of samples, detecting sex chromosome aneuploidies with high sensitivity and specificity.
Nihms379831 stephen quake
This document describes a new noninvasive method for sequencing the entire fetal genome using cell-free DNA found in a pregnant woman's blood. The method works by counting parental haplotypes - combinations of maternal and paternal chromosomes passed to the fetus. Since a small percentage of cell-free DNA comes from the fetus, haplotypes inherited by the fetus can be identified by which have a higher count. Researchers tested this method on two pregnancies and were able to determine the fetal genomes without any invasive procedures. This noninvasive prenatal testing could allow comprehensive screening for genetic diseases.
Twin zygosity nipt
This document describes a study that used massively parallel sequencing of cell-free DNA in maternal blood to assess zygosity and detect fetal aneuploidies in twin pregnancies. The study determined zygosity by analyzing apparent fractional fetal DNA concentrations across genomic regions. It then calculated individual fetal DNA concentrations for dizygotic twins to assess each fetus. The study detected trisomy 21 in one twin and trisomy 18 in the other twin of two pregnancies. It demonstrated that noninvasive prenatal testing for aneuploidies can be achieved for twin pregnancies using this method.
1 s2.0-s0015028213027441-main
This document compares different technologies for 24-chromosome copy number analysis in preimplantation genetic screening and diagnosis. It discusses the differences between screening and diagnostic tests, with screening tests being noninvasive, low-cost and allowing analysis of all patients to prioritize embryos, while diagnostic tests require high accuracy. It reviews technologies for copy number analysis including chromosome spreading, array comparative genomic hybridization, quantitative PCR and next generation sequencing, discussing their advantages and limitations for screening and diagnosis.
Art%3 a10.1007%2fs10815 014-0355-4
This document describes a case study of preimplantation genetic diagnosis (PGD) performed on a breast cancer patient carrying a novel genomic deletion in the BRCA2 gene. Researchers first used single sperm haplotyping on the patient's carrier brother to establish linkage to the mutation. They then used BLAST analysis to locate putative hairpin structures in the genome and PCR screening to identify a 2,596 bp deletion in BRCA2 involving exons 15-16. PGD was performed using both direct mutation detection and linkage analysis to avoid misdiagnosis from recombination. This identified unaffected embryos, one of which was transferred, resulting in a live birth.
Art%3 a10.1007%2fs10815 014-0355-4 (1)
This document describes a case study of preimplantation genetic diagnosis (PGD) performed on a breast cancer patient carrying a novel genomic deletion in the BRCA2 gene. Researchers first used single sperm haplotyping on the patient's carrier brother to establish linkage to the mutation. They then used BLAST analysis to locate putative hairpin structures in the genome and PCR screening to identify a 2,596 bp deletion in BRCA2 involving exons 15-16. PGD was performed using both direct mutation detection and linkage analysis to avoid misdiagnosis from recombination. This identified unaffected embryos, one of which was transferred, resulting in a live birth.
1 s2.0-s0015028214020809-main
The document describes a pilot study that investigated the presence of DNA in blastocyst fluids (BFs) and whether the chromosomal status predicted by analyzing this DNA corresponds to the status in trophectoderm (TE) cells and the whole embryo. The study found that:
1) DNA was detected in the BFs of 76.5% of blastocysts tested, allowing chromosomal analysis of these samples.
2) In 97.4% of cases, the ploidy condition (euploid vs. aneuploid) predicted by BF analysis matched the condition in TE cells.
3) BF analysis predicted the ploidy condition of the whole embryo with 100% accuracy
Art%3 a10.1007%2fs10815 014-0230-3
This study compared two microarray technologies, single nucleotide polymorphism (SNP) and comparative genomic hybridization (aCGH), for preimplantation genetic diagnosis and screening (PGD/PGS) of embryos from couples where one parent has a balanced reciprocal translocation. The study found:
1) There was no significant difference in the rates of euploid embryos without translocation imbalances, euploid embryos with imbalances, or aneuploid embryos between the SNP and aCGH technologies.
2) Clinical pregnancy rates were also equivalent for SNP (60%) and aCGH (65%) microarrays.
3) Both SNP and aCGH microarrays effectively identified unbalanced translocations
1 s2.0-s0015028214018603-main
This document summarizes a study that developed a new microarray platform capable of simultaneously assessing aneuploidy, mitochondrial DNA content, and single-nucleotide polymorphisms in human polar bodies and embryos. The microarray was optimized and validated using cell lines and clinical samples. Results found the microarray detected aneuploidies with 97% accuracy and could accurately determine relative mitochondrial DNA quantities and genotypes, allowing confirmation of parental origin. The microarray provides information beyond chromosomal analysis alone that could improve embryo assessment and selection.
Introduction: Preimplantation genetic screening is alive and very well. Meldr...
This document compares different technologies for 24-chromosome copy number analysis in preimplantation genetic screening and diagnosis. It discusses the differences between screening and diagnostic tests, with screening tests being noninvasive, rapid and lower cost to select embryos, while diagnostic tests require higher accuracy. Technologies reviewed include fluorescence in situ hybridization, comparative genomic hybridization, array comparative genomic hybridization and next generation sequencing, with array CGH currently being the most widely used due to its accuracy and ability to analyze all chromosomes.
New developments in reproductive medicine
1. Approximately 15-20% of couples in Germany experience infertility issues. New developments in reproductive medicine include GnRH-antagonists for ovarian stimulation, elective single embryo transfer (eSET) to reduce multiple pregnancies, blastocyst transfer, in-vitro maturation, and vitrification for cryopreservation.
2. Studies show eSET results in similar pregnancy rates but significantly fewer multiple pregnancies compared to double embryo transfer. Vitrification is an improved cryopreservation technique with higher post-thaw survival and pregnancy rates compared to slow freezing.
3. In-vitro maturation allows retrieval of immature eggs for fertilization, and may help avoid ovarian hyperstimulation syndrome in high-risk patients
New developments in reproductive medicine (1)
1. Approximately 15-20% of couples in Germany experience infertility issues. New developments in reproductive medicine include GnRH-antagonists for ovarian stimulation, elective single embryo transfer (eSET) to reduce multiple pregnancies, blastocyst culture, and vitrification for improved cryopreservation outcomes.
2. Studies show eSET results in similar pregnancy rates but significantly fewer multiple pregnancies compared to double embryo transfer. The use of GnRH-antagonists results in a simplified stimulation protocol with fewer side effects and no difference in live birth rates compared to GnRH-agonists.
3. Vitrification through techniques like the Cryotop method provide significantly better embryo survival and pregnancy rates compared to slow freezing methods
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Introduction: Preimplantation genetic screening is alive and very well. Meldr...
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