Genital Transplants: Is Science Going Too Far, Too Fast?
Thanks to the remarkable evolution of organ transplantation, it's now possible to replace genitals that don't work properly or have been injured. Surgeons have been transplanting ovarian tissue for more than a decade, and they're now successfully transplanting penises and wombs too.
Rules and regulations aren't keeping up with the rapid rise of genital transplants.
Earlier this year, an American soldier whose genitals were injured by a bomb in Afghanistan received the first-ever transplant of a penis and scrotum at Johns Hopkins Medicine.
Rules and regulations aren't keeping up with the rapid rise of genital transplants, however, and there's no consensus about how society should handle a long list of difficult and delicate questions.
Are these expensive transplants worth the risk when other alternatives exist? Should men, famously obsessed with their penises, be able to ask for a better model simply because they want one? And what happens when transplant technology further muddles the concept of biological parenthood?
"We need to remember that the human body is not a machine with interchangeable parts," says bioethicist Craig M. Klugman of DePaul University. "These are complicated, difficult and potentially dangerous surgeries. And they require deep consideration on a physical, psychological, spiritual, and financial level."
From Extra Testicles to Replacement Penises
Tinkering with human genitalia -- especially the male variety -- is hardly a new phenomenon. A French surgeon created artificial penises for injured soldiers in the 16th century. And a bizarre implant craze swept the U.S. in the 1930s when a quack physician convinced men that, quite literally, the more testicles the merrier – and if the human variety wasn't available, then ones from goats would have to do.
Now we're more sophisticated. Modern genital transplants are designed to do two things: Treat infertility (in women) and restore the appearance and function of genitals (in men).
In women, surgeons have successfully transplanted ovarian tissue from one woman to another since the mid-2000s, when an Alabama woman gave birth after getting a transplant from her identical twin sister. Last year, for the first time in the U.S., a young woman gave birth after getting a uterus transplant from a living donor.
"Where do you draw the line? Is pregnancy a privilege? Is it a right?"
As for men, surgeons in the U.S. and South Africa have successfully transplanted penises from dead men into four men whose genitals were injured by a botched circumcision, penile cancer or a wartime injury. One man reportedly fathered a child after the procedure.
The Johns Hopkins procedure was the first to include a scrotum. Testicles, however, were not transplanted due to ethical concerns. Surgeons have successfully transplanted testicles from man-to-man in the past, but this procedure isn't performed because the testes would produce sperm with the donor's DNA. As a result, the recipient could father a baby who is genetically related to the donor.
Are Transplants Worth the Expense and Risk?
Genital transplants are not simple procedures. They're extremely expensive, with a uterus transplant estimated to cost as much as $250,000. They're dangerous, since patients typically must take powerful drugs to keep their immune systems from rejecting their new organs. And they're not medically necessary. All have alternatives that are much less risky and costly.
Dr. Hiten D. Patel, a urologist at Johns Hopkins University, believes these types of factors make penis transplants unnecessary. As he wrote in a 2018 commentary in the journal European Urology, "What in the world are we doing?"
There are similar questions about female genital transplants, which allow infertile women to become pregnant instead of turning to alternatives like adoption or surrogacy. "This is not a life-saving transplant. A woman can very well live without a uterus," says McGill University's Dr. Jacques Balayla, who studies uterine transplantation. "Where do you draw the line? Is pregnancy a privilege? Is it a right? You don't want to cause harm to an individual unless there's an absolute need for the procedure."
But Johns Hopkins urologist Dr. Arthur L. Burnett II, who served on the surgical team that performed the penis-and-scrotum procedure, says penis transplants can be appropriate when other alternatives – like a "neophallus" created from forearm skin and tissue – aren't feasible.
It's also important to "restore normalcy," he says. "We want someone to be able to have sense of male adequacy and a normal sense of bodily well-being on both physical and psychological levels."
Surgical team members who performed the penis transplant, including W. P. Andrew Lee, director of the department of plastic and reconstructive surgery, center.
As for the anonymous recipient, he's reportedly doing "very well" five months after the transplant. An update on Johns Hopkins' website states that "he has normal urinary functions and is beginning to regain sensation in the transplanted tissues."
When the Organ Donors Do It Live
Some peculiar messages reached Burnett's desk after his institution announced it would begin performing penis transplants. Several men wanted to donate their own organs. But for now, transplanted penises are only coming from dead donors whose next of kin have approved the donation.
Burnett doesn't expect live donors to enter the penis transplant picture. But there are no guidelines or policies to stop surgeons from transplanting a penis from a live donor or, for that matter, a testicle.
Live women have already donated wombs and ovarian tissue, forcing them to face their own risks from transplant surgery. "You're putting the donor at risk because she has to undergo pretty expensive surgery for a procedure that is not technically lifesaving," McGill University's Balayla says.
When it comes to uterus transplants, the risk spreads even beyond donor and recipient. Balayla notes there's a third person in the equation: The fetus. "Immunosuppressant medication may harm the baby, and you're feeding the baby with a [uterine] blood vessel that's not natural, held together by stitches," he says.
It's up to each medical institution that performs the procedures to set its own policies.
Bioethicists are talking about other issues raised by genital transplants: How should operations for transgender people fit in? Should men be able to get penis transplants for purely cosmetic reasons? And then there's the looming question of genetic parenthood.
It's up to each medical institution that performs the procedures to set its own policies.
Let's say a woman gets a transplant of ovarian tissue, a man gets a testicle transplant, and they have a baby the old-fashioned way.* The child would be genetically linked to the donors, not the parents who conceived him or her.
Call this a full-employment act not just for bioethicists but theologians too. "Catholicism is generally against reproductive technologies because it removes God from the nature of the procreative act. This technology, though, could result in conception through the natural act. Would their concern remain?" DePaul University's Klugman asked. "Judaism is concerned with knowing a child's parentage, would a child from transplanted testes be the child of the donor or the recipient? Would an act of coitus with a transplanted penis be adultery?"
Yikes. Maybe it's time for the medical field or the law to step in to determine what genital transplants surgeons can and can't -- or shouldn't -- do.
So far, however, only uterus transplants have guidelines in place. Otherwise, it's up to each medical institution that performs the procedures to set its own policies.
"I don't know if the medical establishment is in the position to do the best job of self-regulation," says Lisa Campo-Engelstein, a bioethicist with Albany Medical College. "Reproductive medicine in this country is a huge for-profit industry. There's a possibility of exploitation if we leave this to for-profit fertility companies."
And, as bioethicist Klugman notes, guidelines "aren't laws, and people can and do violate them with no effect."
He doesn't think laws are the solution to the ethical issues raised by genital transplants either. Still, he says, "we do need a national conversation on these topics to help provide guidance for doctors and patients."
[Correction: The following sentence has been updated: "Let's say a woman gets a transplant of ovarian tissue, a man gets a testicle transplant, and they have a baby the old-fashioned way." The original sentence mistakenly read "uterus transplant" instead of "ovarian tissue."]
Gene Transfer Leads to Longer Life and Healthspan
The naked mole rat won’t win any beauty contests, but it could possibly win in the talent category. Its superpower: fighting the aging process to live several times longer than other animals its size, in a state of youthful vigor.
It’s believed that naked mole rats experience all the normal processes of wear and tear over their lifespan, but that they’re exceptionally good at repairing the damage from oxygen free radicals and the DNA errors that accumulate over time. Even though they possess genes that make them vulnerable to cancer, they rarely develop the disease, or any other age-related disease, for that matter. Naked mole rats are known to live for over 40 years without any signs of aging, whereas mice live on average about two years and are highly prone to cancer.
Now, these remarkable animals may be able to share their superpower with other species. In August, a study provided what may be the first proof-of-principle that genetic material transferred from one species can increase both longevity and healthspan in a recipient animal.
There are several theories to explain the naked mole rat’s longevity, but the one explored in the study, published in Nature, is based on the abundance of large-molecule high-molecular mass hyaluronic acid (HMM-HA).
A small molecule version of hyaluronic acid is commonly added to skin moisturizers and cosmetics that are marketed as ways to keep skin youthful, but this version, just applied to the skin, won’t have a dramatic anti-aging effect. The naked mole rat has an abundance of the much-larger molecule, HMM-HA, in the chemical-rich solution between cells throughout its body. But does the HMM-HA actually govern the extraordinary longevity and healthspan of the naked mole rat?
To answer this question, Dr. Vera Gorbunova, a professor of biology and oncology at the University of Rochester, and her team created a mouse model containing the naked mole rat gene hyaluronic acid synthase 2, or nmrHas2. It turned out that the mice receiving this gene during their early developmental stage also expressed HMM-HA.
The researchers found that the effects of the HMM-HA molecule in the mice were marked and diverse, exceeding the expectations of the study’s co-authors. High-molecular mass hyaluronic acid was more abundant in kidneys, muscles and other organs of the Has2 mice compared to control mice.
In addition, the altered mice had a much lower incidence of cancer. Seventy percent of the control mice eventually developed cancer, compared to only 57 percent of the altered mice, even after several techniques were used to induce the disease. The biggest difference occurred in the oldest mice, where the cancer incidence for the Has2 mice and the controls was 47 percent and 83 percent, respectively.
With regard to longevity, Has2 males increased their lifespan by more than 16 percent and the females added 9 percent. “Somehow the effect is much more pronounced in male mice, and we don’t have a perfect answer as to why,” says Dr. Gorbunova. Another improvement was in the healthspan of the altered mice: the number of years they spent in a state of relative youth. There’s a frailty index for mice, which includes body weight, mobility, grip strength, vision and hearing, in addition to overall conditions such as the health of the coat and body temperature. The Has2 mice scored lower in frailty than the controls by all measures. They also performed better in tests of locomotion and coordination, and in bone density.
Gorbunova’s results show that a gene artificially transferred from one species can have a beneficial effect on another species for longevity, something that had never been demonstrated before. This finding is “quite spectacular,” said Steven Austad, a biologist at the University of Alabama at Birmingham, who was not involved in the study.
Just as in lifespan, the effects in various organs and systems varied between the sexes, a common occurrence in longevity research, according to Austad, who authored the book Methuselah’s Zoo and specializes in the biological differences between species. “We have ten drugs that we can give to mice to make them live longer,” he says, “and all of them work better in one sex than in the other.” This suggests that more attention needs to be paid to the different effects of anti-aging strategies between the sexes, as well as gender differences in healthspan.
According to the study authors, the HMM-HA molecule delivered these benefits by reducing inflammation and senescence (cell dysfunction and death). The molecule also caused a variety of other benefits, including an upregulation of genes involved in the function of mitochondria, the powerhouses of the cells. These mechanisms are implicated in the aging process, and in human disease. In humans, virtually all noncommunicable diseases entail an acceleration of the aging process.
So, would the gene that creates HMM-HA have similar benefits for longevity in humans? “We think about these questions a lot,” Gorbunova says. “It’s been done by injections in certain patients, but it has a local effect in the treatment of organs affected by disease,” which could offer some benefits, she added.
“Mice are very short-lived and cancer-prone, and the effects are small,” says Steven Austad, a biologist at the University of Alabama at Birmingham. “But they did live longer and stay healthy longer, which is remarkable.”
As for a gene therapy to introduce the nmrHas2 gene into humans to obtain a global result, she’s skeptical because of the complexity involved. Gorbunova notes that there are potential dangers in introducing an animal gene into humans, such as immune responses or allergic reactions.
Austad is equally cautious about a gene therapy. “What this study says is that you can take something a species does well and transfer at least some of that into a new species. It opens up the way, but you may need to transfer six or eight or ten genes into a human” to get the large effect desired. Humans are much more complex and contain many more genes than mice, and all systems in a biological organism are intricately connected. One naked mole rat gene may not make a big difference when it interacts with human genes, metabolism and physiology.
Still, Austad thinks the possibilities are tantalizing. “Mice are very short-lived and cancer-prone, and the effects are small,” he says. “But they did live longer and stay healthy longer, which is remarkable.”
As for further research, says Austad, “The first place to look is the skin” to see if the nmrHas2 gene and the HMM-HA it produces can reduce the chance of cancer. Austad added that it would be straightforward to use the gene to try to prevent cancer in skin cells in a dish to see if it prevents cancer. It would not be hard to do. “We don’t know of any downsides to hyaluronic acid in skin, because it’s already used in skin products, and you could look at this fairly quickly.”
“Aging mechanisms evolved over a long time,” says Gorbunova, “so in aging there are multiple mechanisms working together that affect each other.” All of these processes could play a part and almost certainly differ from one species to the next.
“HMM-HA molecules are large, but we’re now looking for a small-molecule drug that would slow it’s breakdown,” she says. “And we’re looking for inhibitors, now being tested in mice, that would hinder the breakdown of hyaluronic acid.” Gorbunova has found a natural, plant-based product that acts as an inhibitor and could potentially be taken as a supplement. Ultimately, though, she thinks that drug development will be the safest and most effective approach to delivering HMM-HA for anti-aging.
In recent years, researchers of Alzheimer’s have made progress in figuring out the complex factors that lead to the disease. Yet, the root cause, or causes, of Alzheimer’s are still pretty much a mystery.
In fact, many people get Alzheimer’s even though they lack the gene variant we know can play a role in the disease. This is a critical knowledge gap for research to address because the vast majority of Alzheimer’s patients don’t have this variant.
A new study provides key insights into what’s causing the disease. The research, published in Nature Communications, points to a breakdown over time in the brain’s system for clearing waste, an issue that seems to happen in some people as they get older.
Michael Glickman, a biologist at Technion – Israel Institute of Technology, helped lead this research. I asked him to tell me about his approach to studying how this breakdown occurs in the brain, and how he tested a treatment that has potential to fix the problem at its earliest stages.
Dr. Michael Glickman is internationally renowned for his research on the ubiquitin-proteasome system (UPS), the brain's system for clearing the waste that is involved in diseases such as Huntington's, Alzheimer's, and Parkinson's. He is the head of the Lab for Protein Characterization in the Faculty of Biology at the Technion – Israel Institute of Technology. In the lab, Michael and his team focus on protein recycling and the ubiquitin-proteasome system, which protects against serious diseases like Alzheimer’s, Parkinson’s, cystic fibrosis, and diabetes. After earning his PhD at the University of California at Berkeley in 1994, Michael joined the Technion as a Senior Lecturer in 1998 and has served as a full professor since 2009.
Dr. Michael Glickman