Fixing a Baby’s Abnormal Genes in the Womb May Soon Be Possible
A couple holds up a picture of their ultrasound.
By now you have probably heard something about CRISPR, the simple and relatively inexpensive method of precisely editing the genomes of plants, animals, and humans.
The treatment of disease in fetuses, the liminal category of life between embryos and humans, poses the next frontier.
Through CRISPR and other methods of gene editing, scientists have produced crops to be more nutritious, better able to resist pests, and tolerate droughts; engineered animals ranging from fruit flies to monkeys to make them better suited for scientific study; and experimentally treated the HIV virus, Hepatitis B, and leukemia in human patients.
There are also currently FDA-approved trials to treat blindness, cancer, and sickle cell disease in humans using gene editing, and there is consensus that CRISPR's therapeutic applications will grow significantly in the coming years.
While the treatment of human disease through use of gene editing is not without its medical and ethical concerns, the avoidance of disease in embryos is far more fraught. Nonetheless, Nature reported in November that He Jiankui, a scientist in China, had edited twin embryos to disable a gene called CCR5 in hopes of avoiding transmission of HIV from their HIV-positive father.
Though there are questions about the effectiveness and necessity of this therapy, He reported that sequencing has proven his embryonic gene edits were successful and the twins were "born normal and healthy," although his claims have not been independently verified.
More recently, Denis Rebrikov, a Russian scientist, announced his plans to disable the same gene in embryos to be implanted in HIV-positive women later this year. Futuristic as it may seem, prenatal gene editing is already here.
The treatment of disease in fetuses, the liminal category of life between embryos and humans, poses the next frontier. Numerous conditions—some minor, some resulting in a lifetime of medical treatment, some incompatible with life outside of the womb—can be diagnosed through use of prenatal diagnostic testing. There is promising research suggesting doctors will soon be able to treat or mitigate at least some of them through use of fetal gene editing.
This research could soon present women carrying genetically anomalous fetuses a third option aside from termination or birthing a child who will likely face a challenging and uncertain medical future: Whether to undergo a fetal genetic intervention.
However, genetic intervention will open the door to a host of ethical considerations, particularly with respect to the relationship between pregnant women and prenatal genetic counselors. Current counselors theoretically provide objective information and answer questions rather than advise their pregnant client whether to continue with her pregnancy, despite the risks, or to have an abortion.
In practice, though, prenatal genetic counseling is most often directive, and the nature of the counseling pregnant women receive can depend on numerous factors, including their religious and cultural beliefs, their perceived ability to handle a complicated pregnancy and subsequent birth, and their financial status. Introducing the possibility of a fetal genetic intervention will exacerbate counselor reliance upon these considerations and in some cases lead to counseling that is even more directive.
Some women in the near future will face the choice of whether to abort, keep, or treat a genetically anomalous fetus.
Future counselors will have to figure out under what circumstances it is even appropriate to broach the subject. Should they only discuss therapies that are FDA-approved, or should they mention experimental treatments? What about interventions that are available in Europe or Asia, but banned in the United States? Or even in the best case of scenario of an FDA-approved treatment, should a counselor make reference to it if she knows for a fact that her client cannot possibly afford it?
Beyond the basic question of what information to share, counselors will have to confront the fact that the very notion of fixing or "editing" offspring will be repugnant to many women, and inherent in the suggestion is the stigmatization of individuals with disabilities. Prenatal genetic counselors will be on the forefront of debates surrounding which fetuses should remain as they are and which ones should be altered.
Despite these concerns, some women in the near future will face the choice of whether to abort, keep, or treat a genetically anomalous fetus in utero. Take, for example, a woman who learns during prenatal testing that her fetus has Angelman syndrome, a genetic disorder characterized by intellectual disability, speech impairment, loss of muscle control, epilepsy, and a small head. There is currently no human treatment for Angelman syndrome, which is caused by a loss of function in a single gene, UBE3A.
But scientists at the University of North Carolina have been able to treat Angelman syndrome in fetal mice by reactivating UBE3A through use of a single injection. The therapy has also proven effective in cultured human brain cells. This suggests that a woman might soon have to consider injecting her fetus's brain with a CRISPR concoction custom-designed to target UBE3A, rather than terminate her pregnancy or bring her fetus to term unaltered.
Assuming she receives the adequate information to make an informed choice, she too will face an ethical conundrum. There will be the inherent risks of injecting anything into a developing fetus's brain, including the possibility of infection, brain damage, and miscarriage. But there are also risks specific to gene editing, such as so-called off-target effects, the possibility of impacting genes other than the intended one. Such effects are highly unpredictable and can be difficult to detect. So too is it impossible to predict how altering UBE3A might lead to other genetic and epigenetic changes once the baby is born.
There are no easy answers to the many questions that will arise in this space.
A woman deciding how to act in this scenario must balance these risks against the potential benefits of the therapy, layered on top of her belief system, resources, and personal ethics. The calculus will be different for every woman, and even the same woman might change her mind from one pregnancy to the next based on the severity of the condition diagnosed and other available medical options.
Her genetic counselor, meanwhile, must be sensitive to all of these concerns in helping her make her decision, keeping up to date on the possible new treatments, and carefully choosing which information to disclose in striving to be neutral. There are no easy answers to the many questions that will arise in this space, but better to start thinking about them now, before it is too late.
Sexually Transmitted Infections are on the rise. This drug could stop them.
Cases of gonorrhea, chlamydia and syphilis soared last year, but researchers are finding that a drug known as doxy seems to reduce the number of infections.
Sexually transmitted infections (STIs) are surging across the U.S. to 2.5 million cases in 2021 according to preliminary data from the CDC. A new prevention and treatment strategy now in clinical trials may provide a way to get a handle on them.
It's easy to overlook the soaring rates of gonorrhea, chlamydia, and syphilis because most of those infections have few or no symptoms and can be identified only through testing. But left untreated, they can lead to serious damage to nerves and tissue, resulting in infertility, blindness, and dementia. Infants developing in utero are particularly vulnerable.
Covid-19 played havoc with regular medical treatment and preventive care for many health problems, including STIs. After formal lockdowns ended, many people gradually became more socially engaged, with increases in sexual activity, and may have prioritized these activities over getting back in touch with their doctors.
A second blow to controlling STIs is that family planning clinics are closing left and right because of the Dobbs decision and legislation in many states that curtailed access to an abortion. Discussion has focused on abortion, but those same clinics also play a vital role in the diagnosis and treatment of STIs.
Routine public health is the neglected stepchild of medicine. It is called upon in times of crisis but as that crisis resolves, funding dries up. Labs have atrophied and personnel have been redirected to Covid, “so access to routine screening for STIs has been decimated,” says Jennifer Mahn, director of sexual and clinical health with the National Coalition of STD Directors.
A preview of what we likely are facing comes from Iowa. In 2017, the state legislature restricted funding to family health clinics in four counties, which closed their doors. A year later the statewide rate of gonorrhea skyrocketed from 83 to 153.7 cases per 100,000 people. “Iowa counties with clinic closures had a significantly larger increase,” according to a study published in JAMA. That scenario likely is playing out in countless other regions where access to sexual health care is shrinking; it will be many months before we have the data to know for sure.
A decades-old antibiotic finds a new purpose
Using drugs to protect against HIV, either as post exposure prophylaxis (PEP) or pre-exposure prophylaxis (PrEP), has proven to be quite successful. Researchers wondered if the same approach might be applied to other STIs. They focused on doxycycline, or doxy for short. One of the most commonly prescribed antibiotics in the U.S., it’s a member of the tetracycline family that has been on the market since 1967. It is so safe that it’s used to treat acne.
Two small studies using doxy suggested that it could work to prevent STIs. A handful of clinical trials by different researchers and funding sources set out to generate the additional evidence needed to prove their hypothesis and change the standard of care.
Senior researcher Victor Omollo, with the Kenya Medical Research Institute, noted, “These are prevention interventions that women can control on their own without having to seek or get consent from another person,” as is the case with condom use.
The first with results is the DoxyPEP study, conducted at two sexual health clinics in San Francisco and Seattle. It drew from a mix of transgender women and men who have sex with men, who had at least one diagnosed STI over the last year. The researchers divided the participants into two groups: one with people who were already HIV-positive and engaged in care, while the other group consisted of people who were on PrEP to prevent infection with HIV. For the active part of the study, a subset of the participants received doxy, and the rest of the participants did not.
The researchers intentionally chose to do the study in a population at the highest risk of having STIs, who were very health oriented, and “who were getting screened every three months or so as part of their PrEP program or their HIV care program,” says Connie Celum, a senior researcher at the University of Washington on the study.
Each member of the active group was given a supply of doxy and asked to take two pills within 72 hours of having sex where a condom was not used. The study was supposed to run for two years but, in May, it stopped halfway through, when a safety monitoring board looked at the data and recommended that it would be unethical to continue depriving the control group of the drug’s benefits.
Celum presented these preliminary results from the DoxyPEP study in July at the International AIDS Conference in Montreal. “We saw about a 56 percent reduction in gonorrhea, about 80 percent reduction in chlamydia and syphilis, so very significant reductions, and this is on a per quarter basis,” she told a later webinar.
In Kenya, another study is following a group of cisgender women who are taking the same two-pill regimen to prevent HIV, and the data from this research should become available in 2023. Senior researcher Victor Omollo, with the Kenya Medical Research Institute, noted that “these are prevention interventions that women can control on their own without having to seek or get consent from another person,” as is the case with condom use, another effective prevention tool.
Antibiotic resistance
Antibiotic resistance is a potentially big concern. About 25 percent of gonorrhea strains circulating in the U.S. are resistant to the tetracycline class of drugs, including doxy; rates are higher elsewhere. But resistance often is a matter of degree and can be overcome with a larger or longer dose of the drug, or perhaps with a switch to another drug or a two-drug combination.
Research has shown that an established bacterial infection is more difficult to treat because it is part of a biofilm, which can leave only a small portion or perhaps none of the cell surface exposed to a drug. But a new infection, even one where the bacteria is resistant to a drug, might still be vulnerable to that drug if it's used before the bacterial biofilm can be established. Preliminary data suggests that may be the case with doxyPEP and drug resistant gonorrhea; some but not all new drug resistant infections might be thwarted if they’re treated early enough.
“There are some tradeoffs” to these interventions, Celum says, and people may disagree on the cost of increased resistance balanced against the benefits of treating the STIs and reducing their spread within the community.
Resistance does not seem to be an issue yet for chlamydia and syphilis even though doxy has been a recommended treatment for decades, but a remaining question is whether broader use of doxy will directly worsen antibiotic resistance in gonorrhea, or promote it in other STIs. And how will it affect the gut microbiome?
In addition, Celum notes that we need to understand whether doxy will generate mutations in other bacteria that might contribute to drug resistance for gonorrhea, chlamydia or syphilis. The studies underway aim to provide data to answer these questions.
“There are some tradeoffs” to these interventions, Celum says, and people may disagree on the cost of increased resistance balanced against the benefits of treating the STIs and reducing their spread within the community. That might affect doctors' willingness to prescribe the drug.
Turning research into action
The CDC makes policy recommendations for prevention services such as taking doxy, requiring some and leaving others optional. Celum says the CDC will be reviewing information from her trial at a meeting in December, but probably will wait until that study is published before making recommendations, likely in 2023. The San Francisco Department of Public Health issued its own guidance on October 20th and anecdotally, some doctors around the country are beginning to issue prescriptions for doxy to select patients.
About half of new STIs occur in young people ages 15 to 24, a group that is least likely to regularly see a doctor. And sexual health remains a great taboo for many people who don't want such information on their health record for prying parents, employers or neighbors to find out.
“People will go out of their way and travel extensive distances just to avoid that,” says Mahn, the National Coalition director. “People identify locations where they feel safe, where they feel welcome, where they don't feel judged,” Mahn explains, such as community and family planning clinics. They understand those issues and have fees that vary depending on a person’s ability to pay.
Given that these clinics already are understaffed and underfunded, they will be hard pressed to expand services covering the labor intensive testing and monitoring of a doxyPEP regimen. Sexual health clinics don't even have a separate line item in the federal budget for health. That is something the National Association of STI Directors is pushing for in D.C.
DoxyPEP isn't a panacea, and it isn't for everyone. “We really want to try to reach that population who is most likely going to have an STI in the next year,” says Celum, “Because that's where you are going to have the biggest impact.”
The Friday Five: The plain solution to holiday stress?
In this week's Friday Five, research on how to improve your working memory, the plain old solution to stress, rise of the robot surgeon, tomato brain power, the gut connection to health after strokes - and more.
The Friday Five covers five stories in research that you may have missed this week. There are plenty of controversies and troubling ethical issues in science – and we get into many of them in our online magazine – but this news roundup focuses on scientific creativity and progress to give you a therapeutic dose of inspiration headed into the weekend.
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Here are the promising studies covered in this week's Friday Five:
- How to improve your working memory
- A plain old solution to stress
- Progress on a deadly cancer for first time since 1995*
- Rise of the robot surgeon
- Tomato brain power
And in an honorable mention this week, new research on the gut connection to better brain health after strokes.
* The methodology for this study has come under scrutiny here.