This is an overview of PGD, based on a talk in Hangzhou, china in 2009-11-22.
It contains (not freat) sound that you can hear by clicking on the sound symbol on the lower right corner of the slide.
Pre-implantation genetic diagnosis (PGD) involves testing a single cell from an 8-cell embryo during in vitro fertilization (IVF) to screen for genetic disorders and improve the chances of a normal pregnancy. A cell is removed from the embryo and tested using fluorescence in situ hybridization (FISH) to check chromosome number and size, or polymerase chain reaction (PCR) to test for specific genetic mutations. Embryos found to be free of genetic disorders based on testing are then implanted into the uterus, while affected embryos are not transferred. PGD allows couples at risk of passing on genetic diseases to potentially have healthy children.
Clinical manaement of in vitrofertilizatonwithpreimplantation geneticdiagnosi...t7260678
This document discusses clinical management of in vitro fertilization with preimplantation genetic diagnosis (PGD). It covers:
1. PGD was introduced in 1990 to test embryos for genetic diseases before implantation, reducing risks of terminating or delivering sick children. It has helped couples at high risk of passing on genetic diseases.
2. Studies show PGD is safe when performed by experienced labs, with similar outcomes to regular IVF. The biopsy should remove one cell from day 3 embryos.
3. Optimizing PGD success requires an experienced clinic, skilled embryologists, removing one cell, and transferring high-quality embryos one at a time to avoid multiples. Number of eggs retrieved is a key factor.
This document outlines a clinical commissioning policy for pre-implantation genetic diagnosis (PGD) in England. It defines PGD and its aim to allow couples at significant risk of having a child with a genetic disorder to have a genetically related child at very low risk of the condition. The policy specifies that the NHS will fund three cycles of PGD for couples who have or carry a known genetic abnormality. It was created to provide consistent access to PGD services across England.
Dr. irene souter pgd stickler foundation (6)t7260678
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. While mistakes can occur, studies show PGD results in similar delivery outcomes and malformation rates as ICSI. PGD effectively avoids birth of children with genetic defects but requires genetic counseling given technical limitations.
This is an overview of PGD, based on a talk in Hangzhou, china in 2009-11-22.
It contains (not freat) sound that you can hear by clicking on the sound symbol on the lower right corner of the slide.
Pre-implantation genetic diagnosis (PGD) involves testing a single cell from an 8-cell embryo during in vitro fertilization (IVF) to screen for genetic disorders and improve the chances of a normal pregnancy. A cell is removed from the embryo and tested using fluorescence in situ hybridization (FISH) to check chromosome number and size, or polymerase chain reaction (PCR) to test for specific genetic mutations. Embryos found to be free of genetic disorders based on testing are then implanted into the uterus, while affected embryos are not transferred. PGD allows couples at risk of passing on genetic diseases to potentially have healthy children.
Clinical manaement of in vitrofertilizatonwithpreimplantation geneticdiagnosi...t7260678
This document discusses clinical management of in vitro fertilization with preimplantation genetic diagnosis (PGD). It covers:
1. PGD was introduced in 1990 to test embryos for genetic diseases before implantation, reducing risks of terminating or delivering sick children. It has helped couples at high risk of passing on genetic diseases.
2. Studies show PGD is safe when performed by experienced labs, with similar outcomes to regular IVF. The biopsy should remove one cell from day 3 embryos.
3. Optimizing PGD success requires an experienced clinic, skilled embryologists, removing one cell, and transferring high-quality embryos one at a time to avoid multiples. Number of eggs retrieved is a key factor.
This document outlines a clinical commissioning policy for pre-implantation genetic diagnosis (PGD) in England. It defines PGD and its aim to allow couples at significant risk of having a child with a genetic disorder to have a genetically related child at very low risk of the condition. The policy specifies that the NHS will fund three cycles of PGD for couples who have or carry a known genetic abnormality. It was created to provide consistent access to PGD services across England.
Dr. irene souter pgd stickler foundation (6)t7260678
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. While mistakes can occur, studies show PGD results in similar delivery outcomes and malformation rates as ICSI. PGD effectively avoids birth of children with genetic defects but requires genetic counseling given technical limitations.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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
- 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.
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.
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.
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.
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.
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.
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.
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.
- 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.
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
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
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.
1. USA:
Livingston, NJ
Europe:
Barcelona, Spain
Oxford, UK
Hamburg, Germany
PGD for infertility
SSaannttiiaaggoo MMuunnnnéé
Asia:
Kobe, Japan
South America:
Lima, Peru
2. The majority of embryos wwiitthh ‘‘ggoooodd’’
mmoorrpphhoollooggyy aarree cchhrroommoossoommaallllyy aabbnnoorrmmaall
% chromosomally
abnormal embryos
56% Morphology:
Maternal age
embryos analyzed: 6054. Morphologically normal embryos: 3751. Source: Munné et al. 2007.
Similar results also found by Munne et al 1995, Marquez et al. 2000, Magli et al. 2007.
4. Contradicting PPGGDD rreessuullttss
uussiinngg ddaayy 33 bbiiooppssyy aanndd FFIISSHH
Positive effect
Gianaroli et al. 1999
Munne et al 1999
Gianaroli et al 2001a
Gianaroli et al. 2001b
No effect (small)
Werlin et al. 2003
Jansen et al. 2008
Mersereau et al. 2008
Scholcraft et al. 2009
Negative effect
Mastenbroek et al. 2007
Hardarson et al. 2008
Munne et al. 2003
Gianaroli et al. 2004
Munne et al. 2005
Munne et al 2006
Verlinsky et al. 2005
Colls et al. 2007
Garrisi et al. 2009
Rubio et al. 2009
No effect (Large)
Staessen et al. 2004
Platteau et al. 2005
8. P<0.001
Negative pprreeddiiccttiivvee vvaalluuee
Aneuploidy rates for chromosomes X,Y,13,18,21. Munne et al. 2006 and Reprogenetics data up to
10/2007. Average age 37, Observed: Based on 2300 pregnancies after PGD, Expected: Eiben et al.
1994. Observed and expected adjusted by maternal ages
11. Fetus seldom sseellff ccoorrrreecctt::
iitt’’ss tthhee ppllaacceennttaa tthhaatt bbeeccoommeess aabbnnoorrmmaall
2005, Dev. Biol. 279, 420-432
This work questions the assumption that placental confined mosaicism
is the result of fetal self-correction. At the contrary, it suggests that
normal fetuses may develop abnormal placenta.
14. PGD for AMA: rraannddoommiizzeedd ssttuuddiieess
Implantation Staessen et al. (2004):
17.1%
- No significant differences
- But 2 cells biopsied
11.5%
CONTROL 2-CELLS
BIOPSIED
Staessen et al (2004)
15. Two cell biopsy iiss ddeettrriimmeennttaall
“ The data presented here clearly indicates that two cell
biopsy significantly impacts clinical outcome. Our
previous report providing no arguments in favour of PGS
(Staessen et al., 2004) was criticised by others arguing that
PGS might have been beneficial if only one cell had been
removed (Cohen et al., 2007). In respect to the present
findings, this criticism seems justified”.
P < 0.001
21. All controlled PGD studies oonn iiddiiooppaatthhiicc
RRPPLL sshhooww aa ddeeccrreeaassee iinn mmiissccaarrrriiaaggeess
Idiopathic RPL :
Werlin L, et al. (2003) Preimplantation genetic diagnosis (PGD) as both a
therapeutic and diagnostic tool in assisted reproductive technology.
Fertil Steril, 80:467
Munné et al. (2005) Preimplantation genetic diagnosis reduces pregnancy
loss in women 35 and older with a history of recurrent miscarriages.
Fertil Steril 84:331
Garrisi et al. (2009) Effect of infertility, maternal age, and number of
previous miscarriages on the outcome of preimplantation genetic
diagnosis for idiopathic recurrent pregnancy loss. Fertil. Steril 92: 288
Rubio et al. (in press) Prognosis factors for Preimplantation Genetic
Screening in repeated pregnancy loss. Reprod Biomed Online, in press
22. RReedduuccttiioonn iinn mmiissccaarrrriiaaggeess
iinn RRPPLL aafftteerr PPGGDD
number PGD results according to previous of miscarriages
# previous % loss % loss
miscarriages cycles expected after PGD
2 90 29% 19% N.S.
2 190 38% 9% p0.00.1
Garrisi et al. (2009), and Reprogenetics, unpublished
23. RReedduuccttiioonn iinn mmiissccaarrrriiaaggeess
iinn RRPPLL aafftteerr PPGGDD
PGD results according to age when previous number of
miscarriages is 3-5
maternal % loss % loss
age cycles expected after PGD
35 78 26% 10% p0.025
35 202 39% 13% p0.001
Garrisi et al. (2009), Reprogenetics, unpublished results
24. RReedduuccttiioonn iinn mmiissccaarrrriiaaggeess
iinn RRPPLL aafftteerr PPGGDD
PGD results according to fertility
method cycles % loss % loss %
conception expected after PGD p to term
IVF 115 35% 14% p0.01 34%
natural 124 41% 15% p0.005 37%
Average maternal age: 37.5
Garrisi et al. (2009)
35. array CGH on bbllaassttooccyysstt bbiiooppssiieess::
WWhhyy??
Advantages:
1) More DNA: More robust diagnosis
2) Eliminates some mosaic embryos
3) Reduces error rate
44)) RReedduucceedd iimmppaacctt ooff eemmbbrryyoo bbiiooppssyy
5) Less embryos to process
6) Facilitates single embryo transfer
7) Uterine environment optimized after thaw
37. CGH on blastocyst bbiiooppssiieess::
IImmppllaannttaattiioonn iiss iinnddeeppeennddeenntt ooff aaggee
90
80
70
60
50
40
implantation rate
per replaced
embryo
aneuploidy rate
30
20
10
0
30-34 35-38 39-42 43-45
cycles with all
embryos abnormal
Patients 43 who are eligible for blastocyst transfer have a
95% change of having normal embryos available for transfer
38. Results of aCGH in PB aanndd ddaayy 33 bbiiooppssiieess
ESHRE study: PB data
Average age 40
Cycles 42
Embryo replaced n/a
Reprogenetics: data day 3 biopsy
Average age 40
Cycles 107
Av. Embryos replaced 1.0
Implantation rate n/a
Pregnancy rate 19%
Error rate 11%
Implantation rate 31%
Pregancy rate 26%
Error rate 2% *
* Gutierrez-Mateo et al., Fertil Steril,
accepted
39. SNP and CNP arrays:
For diagnosis of aneuploidy
40. aCGH vs. SNP arrays: GGeennoommee ccoovveerraaggee
# of probe genome
probes size covered
aCGH 4,000 x 150,000 kb = 600.0 Mb (25%)
SNPs 300,000 x 50 kb = 1.5 Mb (0.1%)
41. SNP arrays: TTrreeffff ’’ tteeaamm
vvaalliiddaattiioonn
Comparison of implantation rates for those cases with mixed transfers:
• 33 transfers with a mix of SNP
array normal and abnormal
embryos
Embryo
delivers
Failed
Ongoing
development
PGD
• 17 ongoing / delivered
pregnancies
• 86 total embryos transferred:
- 42 normal
- 44 abnormal
normal 18 24
PGD
abnormal 0 44
P0.01
Scott, PCRS 2010 Slide adapted from R. Scott
42. SNP arrays: TTrreeffff ’’ tteeaamm
Blastocyst biopsy, Cryopreservation, SNP array, transfer in thawed cycle
• N=368
• Two centers: RMANJ, CCRM
• Age = 38.2 years
• Number of prior attempts = 2.4
• Blastocysts transferred = 1.6
•Pregnancy rates:
• clinical: 80%
• ongoing past 1st trimester: 76%
• sustained implantation rate: 60%
• rates equivalent at the two centers (differ by 1%)
Scott, PCRS 2010 Slide adapted from R. Scott