Four articles by the venerable science journalist Sebastian Shaw, from the years 2030, 2040, 2055, and 2070:
January 7, 2030
Facetweet Times "Detecting Genetic Defects Earlier Than Ever" Sebastian Shaw
To learn more about the latest reproductive screening technology, I followed a woman I'll call Aspen on her visit to the Obstetrics and Gynecology center at Mass General Hospital. A 33-year-old professional, she arrived four days after she ovulated. A technician wielded a device the size of a hand vacuum cleaner. The business end was a flat plastic plate the size of an old music CD, and she placed it on Aspen's bare stomach just above her pubic bone. After 30 seconds the technician determined that she did indeed have a fertilized egg on its way down the fallopian tube to her uterus. Aspen was visibly pleased at the good news.
Her expression turned more somber as the technician prepared her for the next step. She had not come here for simple good news -- she was here to rule out bad news that might not be simple.
The ability to detect genetic diseases in a fertilized egg four days after ovulation rather than seven days after is not that important to most women. But to some who are uneasy with abortion, implantation is a key milestone. If the egg is destined to produce a child with a disease, then when an egg is just passing through the uterus, it's not so bad to just let it keep going. Once it has put roots down, it's a harder choice.
Watson and Crick discovered the double helix of DNA in 1953. After decades of intensive scientific efforts, gene sequencing became possible. The human genome was first fully sequenced in 2003, a half-century after Watson and Crick's discovery. This was just one milestone in a research effort that held high promise for saving human lives. But fundamental advances have been slow to yield practical benefits -- many start-ups failed when a marketable product proved to be out of reach. Now the benefits are clear and significant, and with the benefit of 2030 hindsight -- 2020 hindsight is a decade behind us now -- we can see all the obstacles that had to be overcome to move from sequencing the human genome to practical applications. Now we can detect most common errors in the human genome early, when abortion is still possible.
The National Medical Database tells us that in the US, the incidence of genetic diseases has dropped dramatically. The ability to detect massive genetic abnormalities such as Down Syndrome has been around far longer, but now diseases caused by a single errant nucleotide can be reliably detected in the early stages of pregnancy. New cases of cystic fibrosis, Tay-Sachs, Huntington's, Sickle Cell Disease and many others are down sharply. They could be virtually eliminated if two additional conditions were met. One is universal access to high-quality medical care. The other is the willingness of mothers to abort a fetus with an abnormality. The second is of course a moral question, not a medical one. Many women refuse to have the genetic testing performed; even after a serious genetic disease has been diagnosed, about 30% of mothers carry a pregnancy to term.
Some women are unwilling to have an abortion from the moment of conception, usually on religious grounds. For others, unwillingness rises as the fetus becomes larger and more developed. Studies show that in practice, a woman's decision is most strongly influenced by the invasiveness of the abortion procedure -- and advances in technology have made it less and less invasive. A 4-month pregnancy can now be terminated with an hour's procedure under IV sedation and virtually no side effects. The woman's experience is going into a hospital pregnant, falling asleep, and waking up with no signs she can detect that she ever was pregnant.
Earlier-stage pregnancies can be terminated by taking one pill and having a heavy period -- without even the menstrual cramps that most women before the year 2023 considered an inevitable monthly occurrence.
Still, there is a drive for ever-earlier detection. Doctors used to rely on amniocentesis, but this requires the presence of a fair-sized amniotic sac. For the past 8 years or so they have needed only a maternal blood sample to fully sequence a fetus's DNA -- once it has implanted.
Now nearly finishing clinical trials is a technology that allows DNA sequencing before implantation. Aspen is one of the patients in the trials. Having determined that her egg had been fertilized, it was time for the real test.
The sensor was an impressive belt, six inches high, an inch thick and weighing about ten pounds. Given the current state of technology, that is space and weight to hold a lot of sensors -- the sensing power of 4,000 MRI machines of 2010 vintage. Aspen sat in an ordinary armchair as the technician wrapped the belt around her hips. All she had to do was sit still for twenty minutes. After five minutes, as our conversation tapered off, she elected to read. Electronic devices interfere with the sensors, so she read a book -- the old-fashioned kind based on Gutenberg technology.
The other presence in the room was a computer on a cart. Imagine a stack of four microwave ovens. This enormous computing power is required for an astonishingly complicated task. Aspen's fertilized egg had by now divided many times into a ball of cells. The computer needs to detect the minuscule vibrations of the nuclei of the atoms in that little ball, and from that determine the exact sequence of 3 billion base pairs in the simple CGAT genetic code. The mass of surrounding maternal cells all have the same DNA sequence, a background against which this tiny ball of cells is a very faint signal. The computer takes advantage of knowledge of the father's genome, but it is still a very difficult problem.
Once the test was done and the belt removed, Aspen and I were ushered into a doctor's office. A minute later Dr. Michelle Renaud entered, introduced herself, and started talking.
She had bad news. The ball of cells had a genetic abnormality that was inconsistent with life. It might or might not implant, but it would not live long enough to really count as a pregnancy. If Aspen did nothing, she might conceivably miss one menstrual period. But her body would shortly flush out this tiny blob of dead cells. Without the test, a delayed period would just tell her she hadn't gotten pregnant. About a fifth of failures to conceive during any given month are due to problems of just this sort. This result had no adverse implications for Aspen's ability to have a normal baby in the future.
The good news was that she had no life-and-death decision to make about whether to bring a child into the world. Her only choice was whether to take a morning after pill (the newest versions of which have no side effects at all) or let nature take its course. She took the tiny generic pill with her and was told she had a day to take it if she wanted. She scanned a QR-X code with her wristy which would give her access to further information on the situation in however much depth she wanted.
I reached Aspen by phone a week later. Asked how she felt about the experience, she said it was a little disconcerting to think she had produced something so very defective, but well worth it. She planned to go back every month until she did conceive a health baby.
I accompanied three other women that day. Two did not have any fertilized egg at all and never made it to wearing the heavy belt. The fourth was a petite 28-year-old redhead I'll call Martha. She is married to a woman, and was having the test four days after artificial insemination. She went through her half-hour with the belt and was told she had a healthy baby. The test's job is to verify that all the important genes are healthy. But in the process, it inevitably also reveals which healthy variants of those genes are present. A few of them have simple effects. Martha wanted to know, and was told she would have a girl with brown eyes and A-positive blood.
When I followed up with Dr. Renaud, she reported that for Aspen's defective ball of cells the underlying technology could reveal the gender, blood type and eye color it would have had if it had been viable. But revealing those "what-ifs" was not going to be comforting, so the software is configured in the factory to destroy that information once a "not viable" diagnosis is made.
It was no surprise that none of the four patients I followed that day was on course to deliver a baby with what we usually think of as a genetic defect -- since the nonviable ones don't enter our everyday thinking at all. What we call genetic defects are quite rare and always have been.
When this technology emerges from final tests and becomes publicly available, scientists predict more women will choose to have the test and more will abort in case of a defect. In parallel, the genes for ever-rarer diseases are being identified. We will continue to hunt genetic diseases towards extinction.
Another promising technology is in its infancy. It should be possible to apply the same sensing technology earlier, before conception. There is no sperm in the picture yet, but the test could detect the half of the genome that would be contributed by a ripening egg. If the egg has a defect, the couple might just decide not to invite any sperm to meet that particular egg, a decision that is acceptable to most people who are opposed to abortion -- and beneficial to many women like Aspen who would not allow a defective ball of cells to implant but would feel morally uneasy about it.
.... There is more of this story ...
Science Fiction /