News Article | April 17, 2017
Some concerns have been voiced over the way in which a clinic last year created the first three-parent baby born using a new technique. The baby’s birth was exclusively revealed by New Scientist in 2016. John Zhang of the New Hope Fertility Center in New York and his team used a form of mitochondrial replacement therapy to help a woman have a baby without passing on a serious genetic disease carried in the DNA of her mitochondria, the compartments that generate energy in our cells. The method involves placing the DNA from one woman into a donated egg from another, and then fertilising it with sperm. Because the egg contains some mitochondrial DNA from the donor, babies made this way carry genetic material from three different people. The team has now published an account of this procedure and the resulting baby’s health in a peer-reviewed journal, Reproductive BioMedicine Online. It reveals that, seven months after birth, the boy remains healthy, showing no signs of Leigh syndrome – a condition that killed two of his older siblings. But some researchers are raising concerns over the procedural paperwork associated with the treatment. An accompanying editorial written by five researchers on the Reproductive BioMedicine Online editorial board describes Zhang’s work as “an achievement and stepping stone”, but points out that the consent form signed by the woman having the baby did not list the specific risks of mitochondrial replacement. “The authors explain that the patient received extensive counselling over the course of several years, but the final consent form does not record this,” says the editorial. And the woman who donated an egg for the therapy, enabling the mother to have a child that carries someone else’s mitochondria, signed a standard egg donor consent form. “A copy of this form received by Reproductive BioMedicine Online shows that the use of the donated eggs specifically for spindle transfer (for MRT) is not mentioned,” the editorial says. The embryo was created in New York, but Zhang’s team implanted it in the woman’s uterus in Mexico. The editorial states that the team had approval from the Mexican clinic’s Internal Review Board to do this, but had not applied for Internal Review Board approval for the work at the New York clinic. “The editorial is detailed in its criticism,” Darren Griffin, at the University of Kent, UK, said in a statement to the UK Science Media Centre. Criticism of the procedure followed has also come from a paper published in the Journal of Law and the Biosciences on 23 March, before Zhang’s study was released. The paper’s authors, César Palacios-González at King’s College London and María de Jesús Medina-Arellano at the National Autonomous University of Mexico, wrote that under their interpretation of the law, and with the information available at the time of publication of their paper, federal regulations may have been breached in Mexico that govern research into assisted fertilisation. New Scientist was not able to reach Zhang for comment. The study from Zhang and his colleagues reveals that some of the mother’s mitochondrial DNA has been passed on to her baby. This is likely to occur to some degree during the procedure that removes the nucleus from her egg, ready for inserting into a donor egg. It seems that about 5 per cent of the mitochondrial DNA in the embryo came from the mother in this way. It is anticipated that this will not be enough for the boy to develop Leigh syndrome. Some studies suggest faulty DNA needs to exceed at least 60 per cent for this to occur. In his mother’s own cells, 34 per cent of her mitochondria carry the faulty DNA, and she has never shown any symptoms of the disease. “They only had one normal-looking embryo that could be transferred to the patient,” Robin Lovell-Badge of the Francis Crick Institute in London told the Science Media Centre. “They were lucky this was indeed normal, giving rise to a pregnancy, and they were lucky that the proportion of abnormal mitochondrial DNA remained relatively low in most tissues.” But Zhang’s team warns of the potential risk that the mother’s faulty DNA will “bounce back” in the boy, saying it’s crucial for him to be monitored for many years. Some researchers are concerned that the percentage of faulty DNA after mitochondrial replacement might increase over time. Symptoms of Leigh syndrome are normally spotted in the first year of life and death usually results after just a couple of years, and at present the boy is just seven months old. Since the birth of the boy described in the team’s paper, other three-parent babies have been made and born elsewhere. A clinic in Ukraine has told New Scientist that the second of two three-parent-babies created using a different technique in order to overcome infertility has been born. The boy was born on 19 February, following the birth of a girl in January. The clinic says both are healthy, but few further details are available yet. Journal of Law and the Biosciences, DOI: 10.1093/jlb/lsw065 (legal study)
News Article | April 4, 2017
Zika Virus - What You Should Know In 2016, the three-parent baby born in Mexico made headlines. According to a study published by doctors who worked on the project, the success came after scraping through many areas of potential defeat. The treatment leading to the conception of the baby was led by Dr. John Zhang of New York's New Hope Fertility Center. The details have been published in the journal Reproductive BioMedicine Online. The process involved in vitro fertilization (IVF) with mitochondrial replacement therapy (MRT). In the paper, Dr. Zhang and colleagues gave a detailed account of the treatment and discussed the barriers they faced. One was the risk of a child carrying a 2.36 percent to 9.23 percent mitochondrial DNA (mtDNA) mutational load in samples tested. Some mutated mtDNA indeed passed into the embryo, which may cause health problems to the child later in his life. For the conception, the egg carried DNA from the boy's mother and minor amounts of mitochondrial DNA from another healthy female donor. The MRT done was mainly to thwart the transmission of defective mitochondria that carried the fatal nervous system disorder Leigh syndrome. Top stem cell biologist Professor Robin Lovell-Badge of London's Francis Crick Institute hailed the move and called it good news. He said the woman treated was able to have an apparently healthy child without any mitochondrial disease was laudable, but he observed that it was apparent that Zhang and the team were "sailing very close to the wind," and luck also played a good part in the successful outcome. However, Lovell-Badge criticized the American doctors for using electrofusion as a method for moving nuclear DNA, which was being shunned by other researchers because it leads to abnormal embryos. The treatment involved the complex transfer of a nuclear DNA from the mother's egg to a donor egg. In the donor egg, the nuclear DNA from the boy's mother and donor's healthy mitochondrial DNA were housed and facilitated its fertilization by the sperm of the father for developing the embryo. The DNA present in mitochondria has a role in metabolism, but it will not impact appearance and personality. The study says the successful outcome brushed through many risk areas, including the passing of abnormal mitochondria to the embryo, though it stayed below the threshold to initiate any disease. Lovell-Badge told a parliamentary committee that there is some concern, though by luck it led to pregnancy, and the abnormal mitochondrial DNA was also low in most tissues. Since many steps in the creation of three-parent baby would have violated the U.S. federal law, final steps, including the implantation of the embryo into the womb, were done in Mexico. However, in the UK, MRT has got a legal stamp. Hailing the positive side of the treatment, Professor Sir Doug Turnbull, director of the University of Newcastle's Wellcome Centre for Mitochondrial Research, said mitochondrial donation has become an important part in new IVF technique helping women with a mitochondrial DNA mutation issues. In the UK, mitochondrial donation is set to thrive, as the regulatory framework has come in place. A New Castle clinic has been issued a license to start mitochondrial donation for women facing a risk for offspring. © 2017 Tech Times, All rights reserved. Do not reproduce without permission.
News Article | October 26, 2016
It’s a boy! A five-month-old boy is the first baby to be born using a new technique that incorporates DNA from three people, New Scientist can reveal. “This is great news and a huge deal,” says Dusko Ilic at King’s College London, who wasn’t involved in the work. “It’s revolutionary.” The controversial technique, which allows parents with rare genetic mutations to have healthy babies, has only been legally approved in the UK. But the birth of the child, whose Jordanian parents were treated by a US-based team in Mexico, should fast-forward progress around the world, say embryologists. The boy’s mother carries genes for Leigh syndrome, a fatal disorder that affects the developing nervous system. Genes for the disease reside in DNA in the mitochondria, which provide energy for our cells and carry just 37 genes that are passed down to us from our mothers. This is separate from the majority of our DNA, which is housed in each cell’s nucleus. Around a quarter of her mitochondria have the disease-causing mutation. While she is healthy, Leigh syndrome was responsible for the deaths of her first two children. The couple sought out the help of John Zhang and his team at the New Hope Fertility Center in New York City. Zhang has been working on a way to avoid mitochondrial disease using a so-called “three-parent” technique. In theory, there are a few ways of doing this. The method approved in the UK is called pronuclear transfer and involves fertilising both the mother’s egg and a donor egg with the father’s sperm. Before the fertilised eggs start dividing into early-stage embryos, each nucleus is removed. The nucleus from the donor’s fertilised egg is discarded and replaced by that from the mother’s fertilised egg. But this technique wasn’t appropriate for the couple – as Muslims, they were opposed to the destruction of two embryos. So Zhang took a different approach, called spindle nuclear transfer. He removed the nucleus from one of the mother’s eggs and inserted it into a donor egg that had had its own nucleus removed. The resulting egg – with nuclear DNA from the mother and mitochondrial DNA from a donor – was then fertilised with the father’s sperm. Zhang’s team used this approach to create five embryos, only one of which developed normally. This embryo was implanted in the mother and the child was born nine months later. “It’s exciting news,” says Bert Smeets at Maastricht University in the Netherlands. The team will describe the findings at the American Society for Reproductive Medicine’s Scientific Congress in Salt Lake City in October. Neither method has been approved in the US, so Zhang went to Mexico instead, where he says “there are no rules”. He is adamant that he made the right choice. “To save lives is the ethical thing to do,” he says. The team seems to have taken an ethical approach with their technique, says Sian Harding, who reviewed the ethics of the UK procedure. The team avoided destroying embryos, and used a male embryo, so that the resulting child wouldn’t pass on any inherited mitochondrial DNA. “It’s as good as or better than what we’ll do in the UK,” says Harding. A remaining concern is safety. Last time embryologists tried to create a baby using DNA from three people was in the 1990s, when they injected mitochondrial DNA from a donor into another woman’s egg, along with sperm from her partner. Two of the fetuses developed genetic disorders, and the technique was halted by the US Food and Drug Administration. The problem may have arisen from the fetuses having mitochondria from two sources. When Zhang and his colleagues tested the boy’s mitochondria, they found that less than 1 per cent carry the mutation. Hopefully, this is too low to cause any problems; generally it is thought to take around 18 per cent of mitochondria to be affected before problems start. “It’s very good,” says Ilic. Smeets agrees, but cautions that the team should monitor the child to make sure the levels stay low. There’s a chance that faulty mitochondria could be better at replicating, and gradually increase in number, he says. “We need to wait for more births, and to carefully judge them,” says Smeets. Two women, one man and a baby A Jordanian couple has been trying to start a family for almost 20 years. Ten years after they married, she became pregnant, but it ended in the first of four miscarriages. In 2005, the couple gave birth to a baby girl. It was then that they discovered the probable cause of their fertility problems: a genetic mutation in the mother’s mitochondria. Their daughter was born with Leigh syndrome, which affects the brain, muscles and nerves of developing infants. Sadly, she died aged six. The couple’s second child had the same disorder, and lived for 8 months. Using a controversial “three-parent baby” technique (see main story), the boy was born on 6 April 2016. He is showing no signs of disease.
News Article | September 28, 2016
A U.S. doctor treating infertility in New York City made possible the birth of a baby who has the DNA of three genetic parents. John Zhang of the New Hope Fertility Center in Manhattan performed the procedure to help a couple from Jordan who had already lost two children to an inherited neurological disorder called Leigh syndrome. The goal was to help the couple give birth to a healthy baby. The baby's mother has genes for the Leigh syndrome, which is characterized by progressive loss of mental and movement abilities that often become apparent in the first year of life. The condition often results in death within two or three years usually because of respiratory failure. The DNA for this severe neurological condition resides in the mitochondria, the cell's energy source. Mitochondrial DNA is only passed to the children through their mother. The woman already had four pregnancy losses and while she has successfully given birth to two children, they also died because of the syndrome. Tests revealed that while the woman was healthy, about a quarter of her mitochondria carry genes for Leigh syndrome so the couple asked help from Zhang, who decided to use mitochondrial transfer procedure. The procedure involved taking nucleus from one of the mother's eggs and then inserting this into another woman's egg that had its own nucleus removed. The egg is then fertilized using the husband's sperm. Zhang's team produced five embryos but only one of these developed normally. This embryo was then implanted into the mother. Nine months later, the woman gave birth to a baby boy. "Without much ado, it appears the first mitochondrial donation baby was born three months ago. This was an ice-breaker. The baby is reportedly healthy," said Dusko Ilic, from King's College London. Zhang had to go to Mexico to perform the procedure because it is not yet approved in the United States. Nonetheless, some health experts are optimistic that the procedure offers hope to parents who risk transmitting to their children genetic disorders that are potentially deadly. "This work represents an important advancement in reproductive medicine," American Society for Reproductive Medicine president Owen Davis said in a statement. "We look forward to it being an option for patients who risk transmitting mitochondrial diseases to their children." Some fertility experts, however, raised concern saying the boy needs to be monitored to ensure that the faulty DNA does not multiply and eventually cause problems. © 2017 Tech Times, All rights reserved. Do not reproduce without permission.
News Article | September 28, 2016
Scientists say the first baby has been born from a new technique that combines DNA from three people. The goal is to prevent the child from inheriting a fatal genetic disease from the mother. The birth, of a boy, is revealed in a research summary published by the journal Fertility & Sterility. Scientists are scheduled to make a fuller presentation at a meeting next month. The magazine New Scientist said the baby was born five months ago to Jordanian parents, and that they were treated in Mexico by a team led by Dr. John Zhang of the New Hope Fertility Center in New York. The technique is not approved in the United States, but Zhang told the magazine, "To save lives is the ethical thing to do." A spokesman for the fertility center said Zhang was not available for further comment on Tuesday. Others involved in the research referred questions to Zhang. The child was at risk of inheriting DNA for Leigh syndrome, a severe neurological disorder that usually kills within a few years of birth. Only a minority of Leigh syndrome cases are inherited through the type of DNA that is targeted by the new method. The technique involved removing some of the mother's DNA from an egg, and leaving the disease-causing DNA behind. The healthy DNA was slipped into a donor's egg, which was then fertilized. As a result, the baby inherited DNA from both parents and the egg donor.
News Article | October 26, 2016
A baby boy has been born using DNA from three people – the first ever birth resulting from a new technique that helps people with rare genetic diseases have healthy children. The achievement is being hailed as a milestone in fertility medicine, up there with the first IVF baby. But why is it such a big deal? How controversial is the technique? And is it safe? New Scientist answers your burning questions. Who are the boy’s three “parents”? The boy’s mother and father are a Jordanian couple who have already lost two children to a genetic disease called Leigh syndrome. The mother carries genes for this disease in her mitochondrial DNA, which is found in the cell’s energy-generating mitochondria. While we inherit the bulk of our DNA from both parents, mitochondrial DNA is only passed down from our mothers. To avoid passing on the disease-causing mitochondrial DNA, John Zhang and his colleagues at the New Hope Fertility Center in New York City used mitochondria from an egg belonging to another woman – an anonymous donor. How much DNA comes from each person? Almost all of the boy’s DNA will come from his mother and father. That’s because most of our genes – around 20,000 in total – are found in the cell’s nucleus; just 37 are found in the mitochondria. In the new procedure, Zhang’s team removed the nucleus from one of the mother’s eggs and inserted it into a donor egg, which had its own nucleus removed. This egg was then fertilised with the father’s sperm. The resulting embryo therefore had nuclear DNA from its parents and mitochondrial DNA from the donor. What do these 37 mitochondrial genes do? These mainly code for enzymes that keep the mitochondria themselves functioning. While a malfunction can trigger a devastating disease, the genes are unlikely to code for the more obvious traits people inherit from their parents. But because they power cells, mitochondria could indirectly affect other things by altering the way cells function. A few studies have suggested that mitochondrial DNA might influence a person’s athletic ability, how long they will live and even their IQ. The exact mechanisms aren’t clear. Haven’t “three parent” babies been born before? Yes, although using a different technique. Back in the 1990s, Jacques Cohen and his colleagues at the Institute for Reproductive Medicine and Science at Saint Barnabas in New Jersey were the first to inject fluid from healthy eggs – including their mitochondria – into eggs from women who had been through several rounds of failed IVF. The hope was that the donated mitochondria would boost the flagging eggs. The team tried their technique 30 times in 27 people, and 17 babies were born. But two fetuses developed a genetic disorder, in which they lacked an X chromosome. One of these pregnancies resulted in a miscarriage, the other was aborted. This led to safety concerns. In 2001, the US Food and Drug Administration wrote to fertility clinics in the US, asking them to stop using the method, and to instead apply for approval from the FDA itself in all cases. The method, called ooplasmic transfer, fell out of favour at that point. Is the new method safe? As far as safety is concerned, it is too soon to know. The baby boy is the first to be born with the new method, so we have too few births to draw conclusions from. For now, though, it seems that the boy – now 5 months old – is healthy. The primary concerns are that some faulty mitochondria could have slipped through the net. It is virtually impossible to leave behind all the mitochondria from the mother’s egg when removing the nucleus, even with the steadiest hand. And the level of mutated mitochondria that can cause symptoms varies by disease. One concern is that “bad” mitochondria, even in tiny amounts, could be better at replicating than “good” mitochondria – eventually tipping the balance and causing disease further down the line. A second concern is that having mitochondria from two sources could disturb the normal relationship between the nucleus and mitochondria, although it is unclear if this is the case. It is a good sign that the boy is healthy, but he will need to be carefully monitored over the coming years. Is the procedure legal? It depends on where you want to do it. A similar technique was approved in the UK last year, although, as far as we know, no one in the country has tried it yet. Embryologists who want to carry out the procedure in the UK first have to apply for a licence, and then must follow a legal and ethical framework. They must also closely follow the development of any babies that are born. In the US, it is up to the FDA to approve the procedure before it can be legally carried out. The country’s Institute of Medicine recommended that they do this back in February, at least for sons, who won’t be able to pass on any of the mitochondrial DNA they receive from the donor. The FDA has yet to make a decision. Zhang says that he tried to apply for FDA approval, but that the organisation told him there was no department set up that could review his application. So he performed the treatment in Mexico, where, as he puts it “there are no rules”. He hopes to continue his work in Mexico, China and the UK. Why is it so controversial? Some people don’t like the idea of a baby having three biological parents, and argue that mitochondrial DNA goes some way to shaping important characteristics, such as personality. But the scientific consensus is that swapping mitochondria is similar to changing a battery – it’s unlikely to have much, if any, influence over a person’s behaviour. Others have argued that the technique is unnecessary. After all, it won’t help those who have already been born with mitochondrial diseases. Parents often don’t find out they are carriers of these diseases until they give birth to sick children. And those who do know they could pass on a disease have other options, such as using a donor egg. The technique is specifically for people who carry genes for the disease, but want to have a child genetically related to them. Another concern is that, by creating a new mix of genetic material, embryologists are creating lasting genetic changes that will be passed down through generations, before we have a chance to find out if they are dangerous. Some argue that this starts us on a slippery slope of germ-line editing – one that could eventually lead to “designer babies”. Could it have other uses? Potentially. Some embryologists believe that ineffective mitochondria could be the cause of age-related infertility, and that eggs of older women fail to form viable embryos because they essentially lack energy. That’s the idea behind Augment – a treatment that uses mitochondria from a woman’s own ovarian stem cells to rejuvenate her egg cells. The team behind this project announced their first birth last year. However, many in the field remain sceptical – doubting that ovarian stem cells actually exist. If ovarian stem cells don’t exist, but the theory behind the rejuvenation idea stacks up, then mitochondria taken from the eggs of young women could be used as an alternative.
News Article | September 28, 2016
A baby boy, born five months ago, was the first birth using a new technique called spindle nuclear transfer that incorporates DNA from three people, New Scientist has reported. The Jordanian parents traveled to Mexico, along with U.S. scientists to undergo the controversial procedure, which is meant to allow parents carrying genes for fatal rare diseases to have healthy children. Another “three-parent” in-vitro fertilization technique called pronuclear transfer was approved in the U.K. in 2015, but has not been approved in the U.S. Dr. John Zhang, a reproductive endocrinologist from the New Hope Fertility Center in New York City, told New Scientist that the method he used involved removing the nucleus from a donor egg, and inserting the nucleus taken from the mother’s egg, then fertilizing the egg with the father’s sperm. As a result the fertilized egg has mitochondrial DNA from the donor and nuclear DNA from the mother, along with the father’s contribution. The decision to seek help from these specialists came after the couple experienced four miscarriages and the deaths of two children who were both born with Leigh’s syndrome, an often deadly disease that affects babies’ developing nervous system, according to the article. The disease-causing mutation is carried in the mitochondrial DNA of the mother, which was replaced by a donor, but not the nuclear DNA, so the procedure was done to ensure this disease would not be passed down to offspring. Zhang told New Scientist that they went to Mexico where, “there are no rules,” insisting that “to save lives is the ethical thing to do.” There were previous attempts in the 1990s to create a baby by inserting mitochondrial DNA from a donor into the mother’s egg and then adding sperm from her partner. “Some of the babies went on to develop genetic disorders and the technique was banned,” New Scientist wrote. “The problem may have arisen from the babies having mitochondria from two sources.” The team asserts that less than one percent of the boy’s mitochondria carries the mutation and the report noted that about 18 percent of mitochondria would need to be affected for problems to arise. Speaking to The Guardian stem cell scientists Dusko Ilic from King’s College in London said questions still remain. “By performing the treatment in Mexico the team were not subject to the same stringent regulation as some other countries would insist on,” he told The Guardian. “We have no way of knowing how skillful or prepared they were, and this may have been a risky thing to do.” He added, “On the other hand, we have what appears to be a healthy baby. Because it was successful, fewer questions will be raised, but it is important that we still ask them.” It has been reported that the team will further detail their findings next month at the American Society for Reproductive Medicine’s Scientific Congress in Salt Lake City.
News Article | December 1, 2016
A woman gave birth to a healthy baby boy with the DNA of three “parents,” it was announced in September. The controversial procedure, used to circumvent a deadly genetic condition, could become more commonplace, in the wake of its successful outcome. A British organization now recommends the use of mitochondrial replacement therapy, as it’s known, in carefully selected situations. A team from Oregon Health and Science University that has pioneered the technique is also refining how donors and mothers could be selected to improve its efficacy, according to two separate Wednesday announcements. The successful procedure at the New Hope Fertility Center in Manhattan involved using the father’s sperm to fertilize two eggs. But the donor’s nucleus was extracted, and replaced with the mother’s nucleus – thereby getting rid of the diseased mitochondria. The mother had genetic defects that led to mitochondrial problems causing Leigh syndrome – and had previously caused the loss of four pregnancies and two children at young ages. Now the U.K.’s Human Fertilisation and Embryology Authority has issued a report recommending that such procedures “in specific circumstances… be cautiously adopted” to avoid fatal genetic defects. Mitochondrial replacement therapy, as it’s also known, continues to be approved for clinical trials in Britain. But there are still safety issues that need to be determined. The Oregon Health and Sciences University published a study in the latest issue of Nature indicating that the mother and the donor would need to have compatible mitochondrial haplotypes to avoid complications. “Our research has suggested a plausible cause of preferential replication of specific haplotypes that should enable us to zero in on ways to identify better matches between donors and recipients,” said Dmitry Temiakov, of the Roman University School of Osteopathic Medicine, a co-author on the study. The spindle transfer was successfully completed by an Oregon Health and Science University team, they reported in 2014. But they apparently did not bring the fertilized cells to term. John Zhang, the fertility doctor in New York City who conducted the experiment, also monitored the genetic constitution of the child using next generation sequencing. It worked – less than two percent of the mitochondrial DNA in the child’s hair follicles, circumcised foreskin, and other neonatal tissues was from the mother.
News Article | September 28, 2016
A first-of-its-kind procedure has resulted in the birth of a healthy baby boy with the DNA from three “parents,” according to a fertility clinic in New York. The doctors at the New Hope Fertility Center in Manhattan used the father’s sperm to fertilize two eggs—one of his partner, and the other from a donor, according to an advanced abstract of the work. Before the two oocytes could start developing, the doctors extracted the nucleus from the donor egg and replaced it with the mother’s nucleus. Some 40 weeks later, the baby boy was born with the genetic material of the three people – and apparently without the deadly inherited condition, Leigh syndrome. The 36-year-old had genetic mutations in her mitochondrial DNA causing the fatal syndrome. After the loss of four pregnancies and two children at early ages, the parents needed to find a way to get around the mutations in the mother’s mitochondrial DNA. “Human oocytes reconstituted by (spindle nuclear transfer) are capable of producing a healthy live birth,” the authors write in their study, to be presented next month at the annual American Society for Reproductive Medicine conference in Salt Lake City. “SNT may provide a novel treatment option in minimizing pathogenic mtDNA transmission from mothers to their babies.” Another “mitochondrial replacement therapy” called pronuclear transfer has been proven to work similarly to avoid inherited disease. Most recently, the PN transfer method was assessed by a British-Chinese team in the journal Nature in July—and they found drawbacks including decreased fertility and the potential for lingering genetic defects. The spindle transfer was successfully completed by an Oregon Health and Science University team, they reported in 2014. But they apparently did not bring the fertilized cells to term. In the pioneering procedure in New York City, the woman and her husband opted for the experimental spindle nuclear transfer, due to religious reasons. John Zhang, the doctor who conducted the experiment, also monitored the genetic constitution of the child during the procedure using Next Generation Sequencing to ensure the healthy genetic transfer. It appears to have worked, they said. Less than two percent of the mother’s mitochondrial DNA was found in the child’s hair follicles, circumcised foreskin, umbilical blood and other neonatal tissues. “The baby is currently 3-months-old and doing well,” they concluded. News of the novel birth was first reported as an “exclusive” by New Scientist.
News Article | September 28, 2016
Fertility doctors used a controversial technique to create a single egg from two women’s DNA, fertilized it, and watched as it grew into a healthy baby. A baby boy with three biological parents just born after being conceived in Mexico. The infant came into the world thanks to a technique that involves manipulating the genetic material from two mothers before fertilizing the resulting egg with the father’s sperm. Variants of the process have been shunned by regulators in the U.S. despite the chance that they could help parents-to-be avoid passing down some rare genetic disorders. The doctor who led the work, John Zhang of the New Hope Fertility Center in New York, used a process called spindle nuclear transfer to swap parts of the nuclei of five eggs from the boy’s mother into donor eggs before injecting sperm. Four of the five eggs began to grow, but only one developed normally. The goal of the work is to allow mothers carrying genetic mutations that cause mitochondrial diseases, which afflict 1,000 to 4,000 people in the U.S. each year, to give birth to healthy babies. In the case of the couple that Zhang’s team worked with, the mother carries genes for Leigh syndrome, which is fatal. Before giving birth to her son in April, she had already had four miscarriages and two children who died of Leigh syndrome. According to an interview in New Scientist, which first reported the story, Zhang said that U.S. regulations drove his team to move the procedure to Mexico—where, he said, “there are no rules.” If such a statement sounds cavalier, outside scientists who commented on the work suggested that the team behaved ethically. The researchers made sure the baby was male to eliminate the possibility that mitochondrial DNA from the donor egg, which would be passed down through the maternal lineage, would not be inherited by any future generations. This isn’t the first time a child has been born with three parents; the practice dates to the 1990s. In 2000 a girl was born whose parents used a different technique to conceive her, but it was shut down by the FDA the shortly thereafter. A similar process to the one Zhang used has been approved in the U.K. For his part, Zhang has a history of working on the cutting edge of reproductive medicine. Over a decade ago, he implanted embryos with genetic material from three parents into a woman in China, and triplets began to grow. All three died before birth, but doctors at the time felt they might’ve made it if the woman had access to the better medical care available in the U.S.