An Israeli research team says it has developed a new genetic testing model that could spare thousands of expectant parents from needless anxiety — and in some cases, from considering pregnancy termination — by more accurately assessing hereditary disease risk in genetically close-knit populations.
Prof. Idit Maya, acting director of the Genetics Institute at Rabin Medical Center, calls the current global standard “flawed” when applied to communities like Jews, Druze, and Circassians, where shared ancestry naturally leads to higher genetic similarity.
Why Current Testing Sparks False Alarms
Today’s widely used prenatal screening threshold was designed for genetically diverse populations, such as those in the United States or much of Europe. In those cases, a high degree of genetic similarity between two parents can signal an increased risk of passing on rare hereditary diseases.
But in homogenous groups — where generations of endogamy mean elevated genetic overlap is normal — the same threshold often triggers false alarms. That can send couples into a spiral of medical consultations, further tests, and sometimes agonising decisions about whether to continue a pregnancy.
Maya says that under the current system, “many couples are being told they are too closely related genetically, when in fact their actual risk is no higher than average for their community.”
The Communities Most Affected
The research focused on Jewish populations worldwide, but the findings extend to other minority groups with tightly interlinked family trees. That includes Druze villages in northern Israel, Circassian communities in the Golan Heights, and even some global diaspora populations that have remained socially and culturally cohesive for centuries.
In these groups, it’s common for marriages to occur within the community — not necessarily between relatives in the traditional sense, but between people whose families share a lineage stretching back many generations.
The problem is that the “global” genetic risk threshold ignores this baseline similarity. What’s normal for one group might be treated as dangerous according to a one-size-fits-all standard.
How the New Model Works
Instead of flagging couples purely based on their genetic similarity score, Maya’s model adjusts the risk threshold to reflect a community’s natural genetic profile.
The system first maps the group’s baseline similarity level. Then it sets a higher cut-off point for concern, so couples aren’t wrongly classified as high risk just because they belong to a more homogenous population.
According to the Rabin Medical Center team, using this adjusted standard can significantly reduce the number of false-positive risk warnings without compromising the detection of genuine threats.
The Emotional Toll of False Positives
Genetic counsellors say the impact of false alarms isn’t just academic. Expectant parents often describe feeling “ambushed” by test results that suggest their baby is at risk for severe genetic conditions.
One Tel Aviv mother, who asked not to be named, recalled how she and her husband were told early in her pregnancy that they were “too close genetically.” She described sleepless nights, strained conversations with relatives, and a battery of expensive follow-up tests. “In the end,” she said, “everything was fine. But the stress was something I wouldn’t wish on anyone.”
Such cases can also lead to unnecessary pregnancy terminations in families unwilling to take what they’ve been told is a “high genetic risk” — even if the risk is inflated by an inappropriate threshold.
A Shift in Medical Practice?
If adopted, Maya’s model could change how prenatal genetic screening is handled in hospitals and clinics serving homogenous populations. That could include both Israel’s public health system and private providers abroad catering to Jewish or other minority communities.
For medical institutions, the change would mean recalibrating algorithms and retraining staff. For parents, it could mean fewer false alarms and less emotional turmoil.
Here’s how the adjusted system compares with the current global standard:
| Testing Approach | Population Baseline Considered? | False Alarm Risk | Accuracy in Homogenous Groups |
|---|---|---|---|
| Current Global Standard | No | High | Low |
| Maya’s Adjusted Model | Yes | Lower | Higher |
What Comes Next
The Rabin Medical Center team plans to present its findings to the Israeli Ministry of Health later this year, with the goal of integrating the adjusted model into national screening guidelines.
Maya says her group is also in early talks with international genetic research bodies to encourage wider adoption. “This is not just about Israel or the Jewish community,” she said. “It’s about making sure genetic testing reflects the reality of the population being tested.”
Adoption abroad could take time, given the need to collect and analyse baseline genetic data for each target community. But genetic counsellors in North America and Europe say they’re already interested, particularly in clinics serving concentrated diaspora groups.
The Broader Debate on One-Size-Fits-All Medicine
The findings highlight a larger conversation in medicine about the dangers of applying global standards without accounting for cultural and genetic diversity. Critics say it’s part of a pattern — from drug dosage recommendations to diagnostic thresholds — where data from one population is treated as universal.
In genetic testing, the stakes can be particularly high. An overestimated risk can change the course of a family’s life; an underestimated one can leave them unprepared for a serious health challenge.
Maya hopes the study sparks a shift in thinking. “Precision medicine means being precise about the population you’re working with,” she said. “Otherwise you’re just guessing — and sometimes those guesses come at too high a price.”
