The Genetic Testing Referral Gap: Who Reaches Clinics, Who Gets Missed

A study published in The American Journal of Human Genetics in December 2025 analyzed records from 14,669 adults seen in genetics clinics at two major health systems over five years. The findings reveal a pattern that challenges a common assumption about who benefits from genetic testing and why certain populations are underrepresented in genetics care. According to the study, Black patients and patients from socioeconomically disadvantaged neighborhoods reach genetics clinics at dramatically lower rates than White patients or those from wealthier areas. But once these underrepresented patients are evaluated, the pattern shifts: they are more likely to have genetic testing ordered, and patients from lower-income neighborhoods are more likely to receive clinically actionable results.

The available evidence points more strongly to referral-stage barriers than to patient hesitancy. According to the study's lead author, Theodore G. Drivas, MD, PhD, systemic barriers in primary care, including provider knowledge gaps, clinic logistics, and the absence of clear national referral guidelines, are preventing patients who could benefit from ever reaching a genetics clinic.

This article is a NuGeneLabs editorial analysis of that study and its publicly available reporting. NuGeneLabs did not conduct, fund, or participate in the underlying research. All statistical claims are attributed to the original study or to public statements by its authors.

The Core Contradiction

The central finding of the study can be summarized as two data points that move in opposite directions.

According to the study abstract, Black individuals were significantly less likely to be evaluated in an adult genetics clinic, with an odds ratio below 0.65 (p < 2e-16). As reported by the Philadelphia Inquirer, at Penn Medicine's genetics clinic in West Philadelphia, approximately 9% of patients are Black, compared to roughly 25% in the cardiology and endocrinology clinics located in the same facility and approximately 40% of Philadelphia's overall population. According to the study, this underrepresentation was consistent across both sites.

Yet once Black patients were evaluated, they were 35% more likely to have genetic testing ordered than White patients (OR = 1.35, p = 0.005), according to the study abstract. And patients from socioeconomically disadvantaged neighborhoods, independent of race, were more likely to have pathogenic variants identified on testing (OR > 1.01, p < 0.002).

The patients least likely to reach evaluation are, by these measures, among the most likely to have testing ordered and to receive meaningful results once they do.

Who Is Underrepresented and by How Much

Race-based representation gaps

The study examined records from the University of Pennsylvania Health System (UPHS) and Mass General Brigham (MGB), both urban academic health systems with large minoritized populations in their catchment areas. According to the study abstract, the only consistent, statistically significant cross-site difference in representation was an overrepresentation of White individuals and an underrepresentation of Black individuals in adult genetics clinics. The UPHS data included approximately 2.2 million patient visits for individuals 18 and older seen between October 2016 and October 2021.

The Penn-specific figures, as reported by the Philadelphia Inquirer, offer a concrete illustration of the gap. In a facility where one in four patients seen by cardiology and endocrinology is Black, only about one in eleven genetics patients is Black, despite Black residents comprising roughly 40% of the city's population. This is not a marginal difference. It is a substantial drop-off that occurs before any clinical decision about testing is made.

Income-based representation gaps

The income gradient is continuous rather than binary. As reported by the Philadelphia Inquirer, each $10,000 increase in the median household income of a patient's neighborhood was associated with a 2 to 5% higher likelihood of evaluation at a genetics clinic. According to the study abstract, patients from disadvantaged neighborhoods were significantly less likely to be evaluated overall (OR < 0.99 per unit increase in neighborhood advantage, p < 0.0001).

This means the access gap is not limited to patients below a poverty threshold. It scales across the income spectrum, with each step down in neighborhood-level socioeconomic status corresponding to a measurable decrease in the likelihood of reaching genetics services.

Where the Bottleneck Occurs

The study's lead author has stated, as reported by Penn Medicine News, that "the real bottleneck is likely at the referral stage." Systemic barriers in primary care, including knowledge gaps among referring providers, clinic hours, and referral patterns, are, in his assessment, preventing patients who could benefit from reaching genetics services.

Several structural factors compound this referral-stage barrier, based on the study's findings and public statements by its authors.

Provider knowledge gaps. According to the researchers, many primary care and specialty physicians may not recognize when a genetics referral is clinically appropriate, particularly for conditions outside of cancer genetics. Without standardized education on when to refer, the decision depends on individual provider familiarity with genetics, which introduces systematic variation.

Geographic and logistic barriers. As reported by the Philadelphia Inquirer, Drivas noted that many of his patients drive two to three hours to be seen for genetic evaluation. The current wait time at his clinic is approximately three to four months. These are access constraints that disproportionately affect patients with fewer resources, less schedule flexibility, or less access to transportation.

Workforce constraints. The researchers call for expanded workforce training and diversification, as reported by Penn Medicine News, noting the severe shortage of genetics specialists and the lack of diversity in the field. Fewer providers mean longer waits, which compound the referral-stage gap.

Insurance inconsistency. As reported by Penn Medicine News, without clear national guidelines on the importance of genetic testing for many conditions, insurance coverage remains uneven. Providers may be less likely to refer when coverage is uncertain, and patients may be less likely to follow through when cost is unpredictable.

No national referral guidelines for most conditions. According to the study, the absence of standardized referral criteria for genetic evaluation outside of cancer means there is no consistent benchmark for when a referral should happen. This leaves the decision to individual clinical judgment, and the study's data suggests that judgment is exercised unevenly across populations.

The Subjective-Presentation Problem

One of the study's most striking and underreported findings is that the racial disparity in evaluation widens for conditions with more subjective clinical presentations. According to the study abstract, Black individuals were significantly less likely to be evaluated for indications with more subjective presentations, with an odds ratio below 0.33 (p < 0.003).

To put this in context, the overall odds ratio for Black patient evaluation was below 0.65. For conditions where the clinical presentation is less clear-cut and the decision to refer relies more heavily on clinical judgment, the odds ratio drops to below 0.33, roughly half the already-reduced rate.

This finding suggests that the referral gap is not uniform. It appears widest where the decision to refer depends most on individual provider assessment rather than on standardized criteria. Where there is more room for discretion, the disparity increases.

The full journal article likely contains more detail on how the researchers classified conditions as subjective versus objective. This analysis relies on the study's published abstract for this data point and cannot elaborate on the specific condition categories used.

The Cancer Genetics Exception

The study identified one area where racial disparities in evaluation were notably reduced: cancer genetics. In this subspecialty, clear clinical practice guidelines recommend genetic testing for specific patient populations. According to media reporting on the study, where these guidelines exist, Black patients were more likely to be evaluated than White patients for cancer-related genetic risk factors.

This is a significant internal comparison within the study. It suggests that when structured referral criteria are in place, the racial gap in who reaches genetics services may narrow. As reported by Penn Medicine News, the researchers note that large, concerted efforts to develop guidelines in cancer genetics helped address racial disparities in that specific area.

The implication, as framed by the study authors, is that similar guideline development for other adult genetic conditions, such as cardiovascular and kidney diseases, could help reduce disparities in those areas as well. This analysis notes that the cancer genetics comparison is suggestive rather than a controlled test of guideline effectiveness, and other factors may also contribute to the reduced disparity in that subspecialty.

What Happens When Underrepresented Patients Are Actually Evaluated

Testing ordered at higher rates

According to the study abstract, once Black patients reached evaluation in a genetics clinic, they were 35% more likely to have genetic testing ordered compared to White patients (OR = 1.35, p = 0.005). As Drivas stated in the Penn Medicine press release, these findings indicate that minority or lower-income patients "are not hesitant about genetic testing, they simply haven't been informed about the option to receive it."

Higher pathogenic variant identification in disadvantaged neighborhoods

According to the study abstract, patients from socioeconomically disadvantaged neighborhoods were more likely to have pathogenic variants identified on genetic testing (OR > 1.01, p < 0.002), independent of race. The testing itself was, by this measure, more likely to produce a definitive, clinically meaningful result for these patients.

As reported by the Philadelphia Inquirer, Drivas described this as a pattern of relative overtesting in higher socioeconomic brackets and undertesting in lower socioeconomic brackets. His framing is clear: the solution is not to reduce testing for wealthier populations, but to improve access for those currently underserved.

What this suggests about the "patient hesitancy" assumption

Some prior literature has suggested that Black patients and other minority groups may be less likely to agree to genetic testing because of distrust in the medical system rooted in historical injustices. This study points in a different direction. Once Black patients reached evaluation, they were more likely to have genetic testing ordered. As reported by the Philadelphia Inquirer, Drivas noted that while some literature has raised hesitancy as a factor, “we don’t see that in our data.” Based on the available evidence, referral-stage barriers appear more central than patient-side reluctance in explaining underrepresentation in genetics clinics.

 

What Public Discussion Often Gets Wrong

Coverage of genetic testing access disparities frequently relies on framing that this study's data does not fully support. Several common assumptions deserve closer scrutiny in light of these findings.

That disparities primarily reflect patient reluctance. The narrative that underrepresented groups are less willing to participate in genetic testing is not supported by this particular study's data. Once evaluated, Black patients were more likely to have testing ordered, and the study's lead author has stated that the findings do not show hesitancy as the primary driver. This suggests that framing the gap as primarily a demand-side problem may misidentify where the system's barriers are concentrated.

That the disparity is a binary, poverty-line problem. The income data in this study shows a continuous gradient. Each $10,000 step in neighborhood median income corresponds to a measurable change in evaluation likelihood, according to the Philadelphia Inquirer's reporting. Framing genetic testing access as a problem that only affects the poorest populations misses the breadth of the gradient.

That awareness campaigns alone can fix a referral-infrastructure problem. Public awareness of genetic testing has grown significantly, but the bottleneck identified in this study sits at the provider-referral level, not the patient-awareness level. Interventions that target only consumer knowledge do not address the structural factors, such as provider education, referral guidelines, workforce capacity, and insurance consistency, that the study's authors identified as barriers to reaching a genetics clinic.

Why This Matters for Precision Medicine

Precision medicine depends on the assumption that genomic data is representative enough to inform clinical decisions across populations. If the patients who are, according to this study, more likely to receive actionable genetic findings are also the ones least likely to reach evaluation, the resulting evidence base may carry gaps that affect clinical guidelines, drug development, and risk models for everyone.

A separate large-scale study by Penn Medicine researchers, conducted in partnership with the VA's Million Veteran Program and published in Science, found that including diverse genetic backgrounds revealed population-specific associations that were not visible in studies focused primarily on European-descent populations. The referral gap described in this clinical genetics study is one mechanism by which that lack of diversity in genomic data may be perpetuated.

Methodology and Source Transparency

This article is a NuGeneLabs editorial analysis of publicly available information. It is not a systematic review, a meta-analysis, or an independent research study. NuGeneLabs did not collect patient data, run statistical analyses, or generate any of the findings described above.

Primary source. The core evidence comes from: Gold JI, Elkaim Y, Gold NB, et al. "Racial and socioeconomic disparities in genetic evaluation and testing in the adult patient population." The American Journal of Human Genetics, 113(1):29-40, 2026. DOI: 10.1016/j.ajhg.2025.11.010. Published December 19, 2025.

Study parameters. Retrospective analysis of 14,669 individuals seen over a five-year period (October 2016 to October 2021) across adult genetics clinics at the University of Pennsylvania Health System (six hospitals, ten multispecialty centers, south-central Pennsylvania) and Mass General Brigham (Harvard-affiliated, Massachusetts). Both are urban academic health systems. The study used EHR-reported race and neighborhood-level measures of social determinants of health. It focused on germline genetic testing.

Additional sources. This analysis also draws on public media coverage of the study from Penn Medicine News, the Philadelphia Inquirer, Patient Daily, and the Daily Pennsylvanian, as well as public reporting on related research by the same team.

What this analysis does. It synthesizes the study's publicly available findings into an editorial framework organized around the patient journey, from population-level need through referral, evaluation, testing, and outcomes. It identifies patterns, contradictions, and gaps in common public discussion. It does not add new data or make claims beyond what the source base supports.

Limitations

Source base. This analysis is built primarily on one large study and its public reporting. A broader evidence base across multiple studies would strengthen the conclusions. However, the study itself is large (14,669 individuals), multi-site (two major health systems in different states), and published in a leading genetics journal.

Setting. Both study sites are urban academic health systems. Referral patterns, access barriers, and patient demographics may differ in rural, community, or non-academic settings. The findings should not be assumed to generalize to all healthcare environments.

Retrospective design. The study describes associations between demographic factors and genetics clinic access. It does not establish causality for why referral rates differ at the specific rates observed.

EHR-reported race. Race was based on electronic health record data, not patient self-identification. This is a standard limitation in EHR-based research.

Neighborhood-level socioeconomic measures. The study used neighborhood-level median household income and related measures as proxies for individual socioeconomic status. These are approximations, not individual-level data.

Full paper not reviewed. NuGeneLabs has not reviewed the complete journal article behind the publisher's paywall. The odds ratios, p-values, and specific findings cited here are drawn from the published abstract and public reporting. The full paper likely contains supplementary tables, condition-specific breakdowns, and methodological detail that would add depth to this analysis. Sections that would benefit from the full paper are noted throughout.

Scope of populations. The study found consistent cross-site disparities specifically for Black versus White patients. Other racial and ethnic groups did not show a similarly consistent pattern across both sites. This analysis focuses on the Black-White disparity and the income gradient because these are the findings the available data supports most clearly.

Summary of Key Findings

The pattern in the available data is consistent: underrepresentation before evaluation, higher-yield findings after evaluation. Based on this study, the referral stage appears to be where access constraints may be limiting clinical value, more than the testing stage itself. Addressing that bottleneck appears to be a structural challenge, not only a patient-behavior question.

Sources and Further Reading

Gold JI, Elkaim Y, Gold NB, Asher S, Raper A, Condit C, Bogus Z, Elysee I, Hennessy L, Kennedy E, Briere LC, Sweetser DA, Kripke C, Verma A, Salmasian H, Landry L, Nathanson KL, Kallish S, Drivas TG. "Racial and socioeconomic disparities in genetic evaluation and testing in the adult patient population." The American Journal of Human Genetics, 113(1):29-40, 2026. ScienceDirect

"Gaps in genetic testing hit Black, low-income hardest." Penn Medicine News, December 19, 2025. Penn Medicine

"Black and low-income patients face disparities in access to genetic testing, Penn study finds." Philadelphia Inquirer, January 20, 2026. Philadelphia Inquirer

"Study finds major disparities in access to genetic testing for Black and low-income patients." Patient Daily, December 28, 2025. Patient Daily

"Penn researchers note benefits of adult genetic testing in new study." The Daily Pennsylvanian, July 17, 2025. Daily Pennsylvanian

Gold JI, Kripke CM, Regeneron Genetics Center, Penn Medicine BioBank, Drivas TG. "Exclusion-based exome sequencing in critically ill adults 18-40 years old has a 24% diagnostic rate and finds racial disparities in access to genetic testing." The American Journal of Human Genetics, 2025. Cell Press

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