Fixing a Baby’s Abnormal Genes in the Womb May Soon Be Possible
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, Naturereported 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.
If you were one of the millions who masked up, washed your hands thoroughly and socially distanced, pat yourself on the back—you may have helped change the course of human history.
Scientists say that thanks to these safety precautions, which were introduced in early 2020 as a way to stop transmission of the novel COVID-19 virus, a strain of influenza has been completely eliminated. This marks the first time in human history that a virus has been wiped out through non-pharmaceutical interventions, such as vaccines.
The flu shot, explained
Influenza viruses type A and B are responsible for the majority of human illnesses and the flu season.
Centers for Disease Control
For more than a decade, flu shots have protected against two types of the influenza virus–type A and type B. While there are four different strains of influenza in existence (A, B, C, and D), only strains A, B, and C are capable of infecting humans, and only A and B cause pandemics. In other words, if you catch the flu during flu season, you’re most likely sick with flu type A or B.
Flu vaccines contain inactivated—or dead—influenza virus. These inactivated viruses can’t cause sickness in humans, but when administered as part of a vaccine, they teach a person’s immune system to recognize and kill those viruses when they’re encountered in the wild.
Each spring, a panel of experts gives a recommendation to the US Food and Drug Administration on which strains of each flu type to include in that year’s flu vaccine, depending on what surveillance data says is circulating and what they believe is likely to cause the most illness during the upcoming flu season. For the past decade, Americans have had access to vaccines that provide protection against two strains of influenza A and two lineages of influenza B, known as the Victoria lineage and the Yamagata lineage. But this year, the seasonal flu shot won’t include the Yamagata strain, because the Yamagata strain is no longer circulating among humans.
How Yamagata Disappeared
Flu surveillance data from the Global Initiative on Sharing All Influenza Data (GISAID) shows that the Yamagata lineage of flu type B has not been sequenced since April 2020.
Nature
Experts believe that the Yamagata lineage had already been in decline before the pandemic hit, likely because the strain was naturally less capable of infecting large numbers of people compared to the other strains. When the COVID-19 pandemic hit, the resulting safety precautions such as social distancing, isolating, hand-washing, and masking were enough to drive the virus into extinction completely.
Because the strain hasn’t been circulating since 2020, the FDA elected to remove the Yamagata strain from the seasonal flu vaccine. This will mark the first time since 2012 that the annual flu shot will be trivalent (three-component) rather than quadrivalent (four-component).
Should I still get the flu shot?
The flu shot will protect against fewer strains this year—but that doesn’t mean we should skip it. Influenza places a substantial health burden on the United States every year, responsible for hundreds of thousands of hospitalizations and tens of thousands of deaths. The flu shot has been shown to prevent millions of illnesses each year (more than six million during the 2022-2023 season). And while it’s still possible to catch the flu after getting the flu shot, studies show that people are far less likely to be hospitalized or die when they’re vaccinated.
Another unexpected benefit of dropping the Yamagata strain from the seasonal vaccine? This will possibly make production of the flu vaccine faster, and enable manufacturers to make more vaccines, helping countries who have a flu vaccine shortage and potentially saving millions more lives.
After his grandmother’s dementia diagnosis, one man invented a snack to keep her healthy and hydrated.
On a visit to his grandmother’s nursing home in 2016, college student Lewis Hornby made a shocking discovery: Dehydration is a common (and dangerous) problem among seniors—especially those that are diagnosed with dementia.
Hornby’s grandmother, Pat, had always had difficulty keeping up her water intake as she got older, a common issue with seniors. As we age, our body composition changes, and we naturally hold less water than younger adults or children, so it’s easier to become dehydrated quickly if those fluids aren’t replenished. What’s more, our thirst signals diminish naturally as we age as well—meaning our body is not as good as it once was in letting us know that we need to rehydrate. This often creates a perfect storm that commonly leads to dehydration. In Pat’s case, her dehydration was so severe she nearly died.
When Lewis Hornby visited his grandmother at her nursing home afterward, he learned that dehydration especially affects people with dementia, as they often don’t feel thirst cues at all, or may not recognize how to use cups correctly. But while dementia patients often don’t remember to drink water, it seemed to Hornby that they had less problem remembering to eat, particularly candy.
Where people with dementia often forget to drink water, they're more likely to pick up a colorful snack, Hornby found. alzheimers.org.uk
Hornby wanted to create a solution for elderly people who struggled keeping their fluid intake up. He spent the next eighteen months researching and designing a solution and securing funding for his project. In 2019, Hornby won a sizable grant from the Alzheimer’s Society, a UK-based care and research charity for people with dementia and their caregivers. Together, through the charity’s Accelerator Program, they created a bite-sized, sugar-free, edible jelly drop that looked and tasted like candy. The candy, called Jelly Drops, contained 95% water and electrolytes—important minerals that are often lost during dehydration. The final product launched in 2020—and was an immediate success. The drops were able to provide extra hydration to the elderly, as well as help keep dementia patients safe, since dehydration commonly leads to confusion, hospitalization, and sometimes even death.
Not only did Jelly Drops quickly become a favorite snack among dementia patients in the UK, but they were able to provide an additional boost of hydration to hospital workers during the pandemic. In NHS coronavirus hospital wards, patients infected with the virus were regularly given Jelly Drops to keep their fluid levels normal—and staff members snacked on them as well, since long shifts and personal protective equipment (PPE) they were required to wear often left them feeling parched.
In April 2022, Jelly Drops launched in the United States. The company continues to donate 1% of its profits to help fund Alzheimer’s research.