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Embryos Right Genetic Wrongs?

New evidence supports an old idea that embryos with genetic abnormalities can somehow fix themselves early in development.

By | July 8, 2011

THE CENTER FOR PREIMPLANTATION GENETICS, LABCORP

Embryos whose cells acquire too many or too few chromosomes have a diminished chance of surviving to full term. If they do survive, the abnormal count could result in Down syndrome or another chromosomal disorder. But some of these defective embryos can actually fix their genetic mistakes, according to a study reported last week at the European Society of Human Reproduction and Embryology meeting in Stockholm, Sweden.

The idea was originally proposed in the 1990s, but with little evidence and a lot of skepticism, had quickly fallen by the wayside. The new study garners support for this controversial concept that, if true, is certain to impact patients and doctors involved in the infertility treatment, in vitro fertilization (IVF).

"I think this is an important phenomenon to investigate," says Nathan Treff, a reproductive geneticist at Reproductive Medicine Associates of New Jersey in Morristown. "But," he added, "the strength of the evidence must be higher if we are going to help people have healthy children."

Three days after a woman’s eggs are fertilized in culture, many IVF clinics check to see if the 5 to 8 cells of the embryos have the correct number of chromosomes. If some cells have too few or too many chromosomes, the mother is likely to suffer a miscarriage, and the team may recommend against implanting the embryo.

William Kearns, director of the Shady Grove Center for Preimplantation Genetics in Rockville, Maryland, and his team decided to take advantage of this practice to see if the embryos maintained their genetic defects as they developed. Using SNP microarrays, they reassessed abnormal 3-day-old IVF embryos, which their patients had consented to donate to science, two days later. While only a fraction of these abnormal embryos survived those two days, many that did appeared normal.

“To us, this really changes the paradigm for IVF and genetic testing on embryos because most clinics do a biopsy after 3 days, and decide whether or not to discard the embryo,” said Kearns. “This study says maybe we should freeze those abnormal embryos so that they remain in a viable state until we know what our findings mean.”

But how such a chromosomal correction might occur remains a mystery. Kearns speculates that the abnormal cells die or get pushed aside towards a less vital region, such as the placenta, as normal cells divide to form the three germ layers that give rise to the baby itself. Abnormal cells in the placenta would not necessarily kill the fetus, Kearns said. Indeed, investigators reported in 1983 that a small percentage of placental cells have erroneous chromosome counts , leading others to suggest just such an idea, said Joyce Harper, an reproductive geneticist at University College London.

The mechanism by which an embryo could recognize a genetic abnormality and either kill or actively push these cells to the side, however, is a bit hard to imagine, said Mark Martindale, an embryologist at Kewalo Marine Laboratory in Honolulu, Hawaii. “I assume genetic abnormalities would have to be detected on the cell surface, and I have no idea how that would happen at such an early stage.”

Treff questions the validity of the results altogether. He points to the lack of a control, noting that there’s no way to know how accurately Kearns’ microarray technique assessed chromosome number. Kearns countered that he’s previously validated his technique, adding that researchers simply “don’t have the luxury of using human embryos as controls.”

But Harper thinks the finding is quite likely real. At this point, she said, she’s heard enough presentations about embryos with problems at day 3, which somehow subside by day 5, that clinicians should start taking the hint. “Kearns’s study just confirms what we’ve said for years. Do not genetically test the embryo on day 3,” she said, pointing to a recent clinical trial she led that showed no increase in pregnancy rates by screening embryos at this stage. She says until there’s evidence of a benefit from clinical trials, counting embryos' chromosomes prior to implantation need not be done. “It’s just not fair to patients or the to the IVF team to do time-consuming and expensive procedures for no reason. This is a real bee in my bonnet.”

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Avatar of: sms software

Anonymous

July 9, 2011

Embryos technique is one of the most useful techniques that
make us feel free by reducing the respective danger and risk from miscarriage.

http://www.sendgroupsms.com

Avatar of:

Posts: 0

July 9, 2011

Embryos technique is one of the most useful techniques that
make us feel free by reducing the respective danger and risk from miscarriage.

http://www.sendgroupsms.com

Avatar of:

Posts: 0

July 9, 2011

Embryos technique is one of the most useful techniques that
make us feel free by reducing the respective danger and risk from miscarriage.

http://www.sendgroupsms.com

Avatar of:

Posts: 0

July 16, 2011

Bill,

I was thinking the same thing. I haven't read the Science paper yet so I am not sure that they didn't do something like that. This is the third "popular" article or discussion of this technique that I have either read or heard and there seems to be a bit of confusion about the changes made. I think that I will have to read the real thing. I would think that Science News, The Scientist and Science Friday could manage to get it across to me. I am a cell biologist and I would think I should be able to "get it"

-Doug

Avatar of:

Posts: 0

July 16, 2011

Bill,

I was thinking the same thing. I haven't read the Science paper yet so I am not sure that they didn't do something like that. This is the third "popular" article or discussion of this technique that I have either read or heard and there seems to be a bit of confusion about the changes made. I think that I will have to read the real thing. I would think that Science News, The Scientist and Science Friday could manage to get it across to me. I am a cell biologist and I would think I should be able to "get it"

-Doug

Avatar of: Douglas Easton

Anonymous

July 16, 2011

Bill,

I was thinking the same thing. I haven't read the Science paper yet so I am not sure that they didn't do something like that. This is the third "popular" article or discussion of this technique that I have either read or heard and there seems to be a bit of confusion about the changes made. I think that I will have to read the real thing. I would think that Science News, The Scientist and Science Friday could manage to get it across to me. I am a cell biologist and I would think I should be able to "get it"

-Doug

Avatar of: Jerry R

Anonymous

July 19, 2011

Even though this is talking about embryos, how much different is this from transplanting tumors into healthy hosts that end up suppressing tumor growth, as explicated by Mina Bissell's work?

Avatar of:

Posts: 0

July 19, 2011

Even though this is talking about embryos, how much different is this from transplanting tumors into healthy hosts that end up suppressing tumor growth, as explicated by Mina Bissell's work?

Avatar of:

Posts: 0

July 19, 2011

Even though this is talking about embryos, how much different is this from transplanting tumors into healthy hosts that end up suppressing tumor growth, as explicated by Mina Bissell's work?

Avatar of:

Posts: 0

July 20, 2011

Stephen Hawking makes a question in  A Brief History
of Time: "What is it that breathes fire into
the equations and makes a universe for them to describe?"

Did the scientist look
seriously about the electromagnetic envelope of the mitochondrial DNA?

Please, read the
paternal mtDNA heritage theory (ISBN 978-606-92107-1-0).

Abstract: The necessary and sufficient processes to a well
function of the human body are meticulous arranged by specific organizational
cells, so called process bio-managers, using interconditioned procedures,
transmitted through three ways of communication: chemical or “protein channelâ€쳌,
electrical or “ion channelâ€쳌 and mitochondrial or “EMF wireless channelâ€쳌. The
third type is out of the visible and measurable spectrum and raises a new challenge
to the scientist. For this type of bio communication we bring a new theoretical
hypothesis, based on the managerial multidisciplinary analysis of a cybernetic
model proposed by us, by simulating the human body function with the virtual
computerized system based on the management of its total knowledge and its
perfect quality way of function. The main bricks used for this virtual
construction are: the brain, as main bio-processor, and Eve mtDNA and Adam
mtDNA, as bio-antennas. This assembly of the total knowledge, build with “brain
reasoning, biological feeling, and unlimited soul feelingâ€쳌, is called by us
“main decision triangle, IQ-EQ-CQâ€쳌. The main principle of the management of the
total knowledge imposes us to not neglect the information produced by man
during the time, even if it seems creasy at the beginning (see brainstorming
definition). Because in the natural fertilisation the spermatozoids are
naturally equipped with the paternal mtDNA (it looks like reflex clystron power
amplifier, KPA = a veritable main bio-GPS), we consider that the paternal
mitochondria DNA have a very important role in the evolution of the human being
life quality and we have developed a new hypothesis, “Adam mtDNA theoryâ€쳌, in
addition to “Eve mtDNA theoryâ€쳌. Keywords: brain, mitochondria, maternal,
paternal
 

Avatar of:

Posts: 0

July 20, 2011

Stephen Hawking makes a question in  A Brief History
of Time: "What is it that breathes fire into
the equations and makes a universe for them to describe?"

Did the scientist look
seriously about the electromagnetic envelope of the mitochondrial DNA?

Please, read the
paternal mtDNA heritage theory (ISBN 978-606-92107-1-0).

Abstract: The necessary and sufficient processes to a well
function of the human body are meticulous arranged by specific organizational
cells, so called process bio-managers, using interconditioned procedures,
transmitted through three ways of communication: chemical or “protein channelâ€쳌,
electrical or “ion channelâ€쳌 and mitochondrial or “EMF wireless channelâ€쳌. The
third type is out of the visible and measurable spectrum and raises a new challenge
to the scientist. For this type of bio communication we bring a new theoretical
hypothesis, based on the managerial multidisciplinary analysis of a cybernetic
model proposed by us, by simulating the human body function with the virtual
computerized system based on the management of its total knowledge and its
perfect quality way of function. The main bricks used for this virtual
construction are: the brain, as main bio-processor, and Eve mtDNA and Adam
mtDNA, as bio-antennas. This assembly of the total knowledge, build with “brain
reasoning, biological feeling, and unlimited soul feelingâ€쳌, is called by us
“main decision triangle, IQ-EQ-CQâ€쳌. The main principle of the management of the
total knowledge imposes us to not neglect the information produced by man
during the time, even if it seems creasy at the beginning (see brainstorming
definition). Because in the natural fertilisation the spermatozoids are
naturally equipped with the paternal mtDNA (it looks like reflex clystron power
amplifier, KPA = a veritable main bio-GPS), we consider that the paternal
mitochondria DNA have a very important role in the evolution of the human being
life quality and we have developed a new hypothesis, “Adam mtDNA theoryâ€쳌, in
addition to “Eve mtDNA theoryâ€쳌. Keywords: brain, mitochondria, maternal,
paternal
 

Avatar of: Alexandru Boris Cosciug

Anonymous

July 20, 2011

Stephen Hawking makes a question in  A Brief History
of Time: "What is it that breathes fire into
the equations and makes a universe for them to describe?"

Did the scientist look
seriously about the electromagnetic envelope of the mitochondrial DNA?

Please, read the
paternal mtDNA heritage theory (ISBN 978-606-92107-1-0).

Abstract: The necessary and sufficient processes to a well
function of the human body are meticulous arranged by specific organizational
cells, so called process bio-managers, using interconditioned procedures,
transmitted through three ways of communication: chemical or “protein channelâ€쳌,
electrical or “ion channelâ€쳌 and mitochondrial or “EMF wireless channelâ€쳌. The
third type is out of the visible and measurable spectrum and raises a new challenge
to the scientist. For this type of bio communication we bring a new theoretical
hypothesis, based on the managerial multidisciplinary analysis of a cybernetic
model proposed by us, by simulating the human body function with the virtual
computerized system based on the management of its total knowledge and its
perfect quality way of function. The main bricks used for this virtual
construction are: the brain, as main bio-processor, and Eve mtDNA and Adam
mtDNA, as bio-antennas. This assembly of the total knowledge, build with “brain
reasoning, biological feeling, and unlimited soul feelingâ€쳌, is called by us
“main decision triangle, IQ-EQ-CQâ€쳌. The main principle of the management of the
total knowledge imposes us to not neglect the information produced by man
during the time, even if it seems creasy at the beginning (see brainstorming
definition). Because in the natural fertilisation the spermatozoids are
naturally equipped with the paternal mtDNA (it looks like reflex clystron power
amplifier, KPA = a veritable main bio-GPS), we consider that the paternal
mitochondria DNA have a very important role in the evolution of the human being
life quality and we have developed a new hypothesis, “Adam mtDNA theoryâ€쳌, in
addition to “Eve mtDNA theoryâ€쳌. Keywords: brain, mitochondria, maternal,
paternal
 

Avatar of: sms software

Anonymous

July 25, 2011


Embryos technique is
one of the most useful techniques that make us feel free by reducing the
respective danger and risk from miscarriage.
 

Avatar of:

Posts: 0

July 25, 2011


Embryos technique is
one of the most useful techniques that make us feel free by reducing the
respective danger and risk from miscarriage.
 

Avatar of:

Posts: 0

July 25, 2011


Embryos technique is
one of the most useful techniques that make us feel free by reducing the
respective danger and risk from miscarriage.
 

Avatar of:

Posts: 0

July 28, 2011

I have performing day 3 PGD for a number of years. The blastomeres were probed for eight chromosomes. Sometimes, the "abnormal" embryos looked better than then the normally proved embryos. When problems with chromosomes other than 13, 18 & 21 came back on the biopsy results, we considered transferring them hoping that they may have "auto-corrected". While some of these embryos didn't implant and I think we had one or two miscarriages, we had five normal deliveries occur where the children were examined in utero or post delivery with karyotype studies. All were normal and yet the embryos had probed abnormal.

One particular case was very interesting. Two blastomeres were removed by accident and both sent. One came back 47,XX+21 and the other 46,XX. Understanding that this was a clear example of a mosaic and the fact that this was the only viable embryo we had, we transferred this embryo on day five with all agreeing that genetic studies needed to be done in utero. Chorionic Villus Sampling (CVS) was performed resulting in 46,XX cell lines only. A normal female was delivered months later. The idea that embryos are commonly mosiac may be a likely cause for some of the differences we see between day 3 and day 5 biopsies. We may find that many embryos are combinations of normal and abnormal cells.

Depending on the genetic problem, it is also likely that normal cells will divide faster than abnormal cells. Abnormal cells may also die leading to fragmentation. If the embryos are indeed mosics, simply removing one abnormal blastomere may also tip the balance towards a greater percentage of normal cells remaining in the early embryo predisposing to auto-correction.

The point is that embryos do self-correct and probably do so more often than the 15% that has been previously reported. There are issues with waiting until day 5 to biopsy but I thought I would provide this perspective on this article and the general discussion.

Craig R. Sweet, M.D.
Reproductive Endocrinologist
Medical & Practice Director
Specialists In Reproductive Medicine & Surgery, P.A.
DrSweet@DreamABaby.com
www.DreamABaby.com

Avatar of:

Posts: 0

July 28, 2011

I have performing day 3 PGD for a number of years. The blastomeres were probed for eight chromosomes. Sometimes, the "abnormal" embryos looked better than then the normally proved embryos. When problems with chromosomes other than 13, 18 & 21 came back on the biopsy results, we considered transferring them hoping that they may have "auto-corrected". While some of these embryos didn't implant and I think we had one or two miscarriages, we had five normal deliveries occur where the children were examined in utero or post delivery with karyotype studies. All were normal and yet the embryos had probed abnormal.

One particular case was very interesting. Two blastomeres were removed by accident and both sent. One came back 47,XX+21 and the other 46,XX. Understanding that this was a clear example of a mosaic and the fact that this was the only viable embryo we had, we transferred this embryo on day five with all agreeing that genetic studies needed to be done in utero. Chorionic Villus Sampling (CVS) was performed resulting in 46,XX cell lines only. A normal female was delivered months later. The idea that embryos are commonly mosiac may be a likely cause for some of the differences we see between day 3 and day 5 biopsies. We may find that many embryos are combinations of normal and abnormal cells.

Depending on the genetic problem, it is also likely that normal cells will divide faster than abnormal cells. Abnormal cells may also die leading to fragmentation. If the embryos are indeed mosics, simply removing one abnormal blastomere may also tip the balance towards a greater percentage of normal cells remaining in the early embryo predisposing to auto-correction.

The point is that embryos do self-correct and probably do so more often than the 15% that has been previously reported. There are issues with waiting until day 5 to biopsy but I thought I would provide this perspective on this article and the general discussion.

Craig R. Sweet, M.D.
Reproductive Endocrinologist
Medical & Practice Director
Specialists In Reproductive Medicine & Surgery, P.A.
DrSweet@DreamABaby.com
www.DreamABaby.com

Avatar of: Drsweet

Anonymous

July 28, 2011

I have performing day 3 PGD for a number of years. The blastomeres were probed for eight chromosomes. Sometimes, the "abnormal" embryos looked better than then the normally proved embryos. When problems with chromosomes other than 13, 18 & 21 came back on the biopsy results, we considered transferring them hoping that they may have "auto-corrected". While some of these embryos didn't implant and I think we had one or two miscarriages, we had five normal deliveries occur where the children were examined in utero or post delivery with karyotype studies. All were normal and yet the embryos had probed abnormal.

One particular case was very interesting. Two blastomeres were removed by accident and both sent. One came back 47,XX+21 and the other 46,XX. Understanding that this was a clear example of a mosaic and the fact that this was the only viable embryo we had, we transferred this embryo on day five with all agreeing that genetic studies needed to be done in utero. Chorionic Villus Sampling (CVS) was performed resulting in 46,XX cell lines only. A normal female was delivered months later. The idea that embryos are commonly mosiac may be a likely cause for some of the differences we see between day 3 and day 5 biopsies. We may find that many embryos are combinations of normal and abnormal cells.

Depending on the genetic problem, it is also likely that normal cells will divide faster than abnormal cells. Abnormal cells may also die leading to fragmentation. If the embryos are indeed mosics, simply removing one abnormal blastomere may also tip the balance towards a greater percentage of normal cells remaining in the early embryo predisposing to auto-correction.

The point is that embryos do self-correct and probably do so more often than the 15% that has been previously reported. There are issues with waiting until day 5 to biopsy but I thought I would provide this perspective on this article and the general discussion.

Craig R. Sweet, M.D.
Reproductive Endocrinologist
Medical & Practice Director
Specialists In Reproductive Medicine & Surgery, P.A.
DrSweet@DreamABaby.com
www.DreamABaby.com

Avatar of: Christine P

Anonymous

August 4, 2011

Would this have implications regarding the accuracy of amniocentesis?

Avatar of:

Posts: 0

August 4, 2011

Would this have implications regarding the accuracy of amniocentesis?

Avatar of:

Posts: 0

August 4, 2011

Would this have implications regarding the accuracy of amniocentesis?

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