Reproductive and General Genetics News: PGT-A, A Unique Paternity Test, and Ongoing Concerns About Genetic Discrimination
Today’s posting offers a look at recent news related to genetics, including a surprising review on PGT-A from some of its biggest proponents – who acknowledged some “uncertainty”surrounding the test. Also included is an unusual story about a woman in a relationship with identical twins, and how a genetic test failed to determine which identical twin fathered the woman’s baby. As always, we welcome your comments and opinions.
The CHR’s Editorial Staff
An Interesting Assessment of PGT-A From a Group of Very Well-Known Proponents
Papers – like people – sometimes offer messages between the lines, and one such paper is what we are commenting on here. Five well-known colleagues who – as strong proponents of Preimplantation Genetic Testing for Aneuploidy (PGT-A) – all have extensively published on the subject, got together and in Human Reproduction basically wrote an Opinion article in the format of a Mini Review (whatever that may mean) on the current status of PGT-A, under the heading, “Navigating uncertainty in PGT-A: aligning analytical, biological, and clinical evidence.”1
And you may ask, - so what, - what makes this a worthwhile article to consider?
The answer is, - that there is probably more interesting stuff in this opinion article than may appear on first impression because, even the notion of “uncertainty” is already remarkable progress, considering how “certain” the PGT-A establishment has been about all of its positions in the past.
Who doesn’t remember the days when we were told PGT-A improved IVF outcomes and everybody who didn’t believe it was crucified? Or who doesn’t remember the days when we were told that every PGT-A diagnosis is binary, - either euploid or aneuploid, and whatever is aneuploid must be disposed?
And then, in 2016, a so-called society of experts in PGT-A (in reality, a coalition of mostly economically interested individuals who profited financially from increasing utilization of PGT-A) published truly absurd new guidelines because none of their prior positions were sustainable anymore and added the alleged diagnosis of “mosaicism” to PGT-A. You may have noted the wording of this last sentence with the emphasis being on “diagnosis” rather than “determination” (anybody can reach a diagnosis, but a determination is expected to reflect reality) because – as it turned out – those experts didn’t even understand the physiological definition of “mosaicism” when calling an embryo with more than just one euploid cell lineage in a tiny number of 5-maximally 10 trophectoderm cells “mosaic” (obviously, only a whole organism can be “mosaic”).
And we, of course, could go on and on about all the certainty proponents projected in their pronouncements over more than 20 years of supporting the ever-increasing utilization of PGT-A. But we, instead, want to quote from their abstract (with mild edits) because it – to a degree, surprisingly, after over 20 years of more-or-less hogwash – presented a very reasonably updated viewpoint, - even if unnecessarily complicated when spelled out:
PGT-A is widely used to guide embryo selection, yet its analytical performance, interpretive consistency, and clinical value remain active areas of debate. Advances in sequencing and haplotype-based methods have improved resolution and enabled classification of aneuploidies by their mechanistic origin. They, however, have also revealed substantial variability between platforms, laboratory thresholds, and reporting practices. As a result, the same embryo may receive different classifications depending on the analytical framework, with direct implications for transfer decisions and cumulative live birth potential. Across the available evidence, whole-chromosome meiotic aneuploidies show consistent patterns that support their clinical relevance. In contrast, diagnoses of chromosomal mosaicism and segmental abnormalities remain variable and less consistently predictive. Taken together, these observations underscore the need for validation frameworks that integrate analytical precision, biological plausibility, and outcome-anchored clinical data. Without such measures, increasing technological complexity risks widening…”
Between the lines – even if it hurts – the message is clear and can be formulated in much simpler ways:
(i) The primary purpose of IVF is the achievement of pregnancy.
(ii) The embryo cohort generated in an IVF cycle, through quantity and quality of these embryos, represents a large majority of the cumulative pregnancy and live birth chances of this cycle to achieve this goal.
(iii) Best IVF practice mandates, therefore, to maximize the chances of pregnancy and live birth by safely maximizing embryo quality and quantity.
(iv) Since, as this Mini Review acknowledged, current PGT-A does not yet allow the categorical distinction between definitely “euploid” and definitely “aneuploid” embryo, PGT-A will always result in non-use or disposal of embryos with normal pregnancy potential.
(v) The routine use of PGT-A, therefore, is not only non-sensical, - but unethical.
REFERENCE
Popovic et al., Hum Reprod 2026;41(5):665-676
A Case Where Even Genetic Testing Could Not Establish Paternity
So imagine, - a woman has a relationship with two identical twins and she conceives. Everybody now wants to know who the father is, including a court. And if you think that this is a made-up story, you are mistaken; it really happened, and a panel of judges just ruled that it is impossible to determine which of the two identical twins fathered the baby.
REFERENCE
Rudy M. FOX News. April 1, 2026. https://www.aol.com/articles/woman-double-twin-relationship-sparks-210521899.html
The Concern about Genetic Discrimination by Insurance Companies
It is interesting that out of all medical and science journals, Science picked up on this issue in a recent article on genetics and the law. And the two authors did a terrific job in explaining a very complex issue.1 While the U.S. Congress passed in 2008 the so-called Genetic Information Nondiscrimination Act (GINA), - most of the heavy lifting regarding the subject was left to the states. In many – if not most – states, the issues, however, remain unresolved or have been only partially resolved. We clearly are all at risk of being discriminated against by insurance companies based on our supposed private and confidential genetic makeup that, likely, is at least theoretically accessible by all kinds of dark sources. Rumor has it, for example, that China is building genetic information banks not only of its own citizens but also of us, - members of the Western world.
We recommend this brief article. It is eye-opening!
REFERENCE
Prince AER, Eckel T. Science 10.1126/science.aee2317