Journal of Atherosclerosis and Thrombosis
Online ISSN : 1880-3873
Print ISSN : 1340-3478
ISSN-L : 1340-3478
Review
The Role of Polygenic Risk Score in the General Population: Current Status and Future Prospects
Masato TakaseAtsushi Hozawa
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2025 Volume 32 Issue 9 Pages 1079-1097

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Abstract

Polygenic risk scores (PRSs), constructed from numerous common single nucleotide polymorphisms (SNPs), have emerged as useful tools for predicting future atherosclerotic cardiovascular disease (ASCVD). PRSs have shown independent associations with ASCVD outcomes and are increasingly being considered to enhance risk stratification and guide primary prevention strategies. However, most evidence to date has been derived from populations of European ancestry, and their generalizability to other populations, including East Asians, remains uncertain. This review summarizes the current epidemiological evidence on the association between PRS and ASCVD outcomes, focusing on findings in Japanese cohorts. We discuss the potential of PRS as a clinical decision support tool, its incremental value over traditional risk factors, and its role in the early identification of high-risk individuals. We also highlight the limited number of prospective studies in the Japanese population, where validation and implementation studies are ongoing. Given the growing accessibility of genetic testing and the potential of PRS to complement conventional risk assessments, further large-scale studies are warranted to evaluate its clinical utility across diverse populations. Expanding ancestry-specific biobanks and improving PRS transferability are essential steps toward the equitable implementation of genomic risk prediction in ASCVD prevention.

1.Introduction

Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of morbidity and mortality worldwide 1). In Japan, ASCVD has consistently ranked among the leading causes of death, placing a growing burden on the healthcare system and underscoring the urgent need for effective prevention strategies 2).

Considerable efforts have been devoted to risk prediction and modification of known risk factors as a primary prevention strategy to reduce the burden of ASCVD 3, 4). Over the past five decades, numerous well-designed epidemiological studies have identified key ASCVD risk factors, including blood pressure (BP), lipid levels, glucose levels, smoking, alcohol consumption, obesity, physical inactivity, and diet 5-11). However, it is widely recognized that these factors do not fully account for the risk of ASCVD, as genetic predisposition also plays a substantial role in its development 11).

Incorporating genetic information into risk assessment may allow earlier identification of individuals at high risk for ASCVD and support the development of personalized prevention strategies from a younger age 4, 12). To date, genetic risk in clinical settings has typically been assessed using family history. Epidemiological studies have shown that having a parent with a history of ASCVD is strongly associated with an elevated risk of ASCVD, independent of conventional risk factors13, 14). Although family history is often used as a proxy for inherited genetic risk, it may also reflect shared environmental risk factors, including lifestyle habits. Thus, the observed associations could arise from a combination of genetic and non-genetic influences or even from complex interactions between them. Nonetheless, the fact that this association remained after adjusting for lifestyle-related factors suggests that unidentified genetic components may contribute to susceptibility to ASCVD.

Monogenic risk variants, which are typically inherited according to Mendelian patterns, are rare in the general population, and confer a large increase in disease risk15). For example, variants in the low-density lipoprotein (LDL) receptor gene that cause familial hypercholesterolemia are strongly associated with ASCVD16, 17). Because of their clinical significance, these monogenic variants are a primary focus in cardiovascular genetics. However, such variants are found in only a small minority of individuals and account for a limited proportion of heritable cardiovascular disease risk. Many patients who develop ASCVD do not carry any known monogenic variants18). These observations support growing evidence that in addition to rare monogenic variants, common genetic variants—those present in at least 1% of the population—also contribute substantially to susceptibility to ASCVD18, 19).

The decreasing cost of genetic testing has facilitated large-scale genome-wide association studies (GWAS), many now involving over one million individuals20-24). These studies have identified numerous single nucleotide variants (SNVs) associated with ASCVD and related traits, including stroke, myocardial infarction, diabetes, BP, and lipid levels20-25). Although the effect size of each common variant is modest in comparison to monogenic mutations, their cumulative impact on disease risk is substantial. Polygenic risk scores (PRSs), also known as polygenic scores or polygenic indices, aggregate the effects of multiple SNVs identified through GWAS and are typically weighted by their estimated effect sizes. Multiple studies have demonstrated that the PRS of ASCVD is associated with the risk of ASCVD4, 19). Unlike rare monogenic mutations, which affect only a small fraction of individuals, PRSs can identify much larger segments of the population at comparable or even higher genetic risk. In this context, PRSs have emerged as a promising risk modifier that can capture genetic predispositions beyond a recorded family history. The enthusiasm for their use has grown rapidly; however, this has arguably outpaced the rigorous evaluation needed to define their clinical utility.

Despite the 2021 European Society of Cardiology (ESC) prevention guidelines recommending against the use of PRSs in clinical practice, these scores are already commercially available and adopted by some clinicians and patients26). Their expanding application reflects both interest and ongoing uncertainty regarding when and how PRSs should be used in cardiovascular risk assessment. A 2022 Scientific Statement from the American Heart Association (AHA) also noted that PRSs offer promising clinical value and are already being used in select contexts4). Nonetheless, the statement emphasized that further evaluation, standardization, and evidence development are essential before widespread implementation. The increasing availability of genetic data in large population-based cohorts now provides an opportunity to enhance our understanding of the pathogenesis of ASCVD, particularly components that are not fully explained by environmental exposure alone.

With the growing availability of PRSs through both academic research and direct-to-consumer platforms, the integration of genetic information into cardiovascular disease prevention has moved beyond theoretical interest to practical relevance27). Despite increasing global attention, the clinical utility of PRSs remains underexplored in Asian populations, including Japan, where genetic architectures and environmental exposures may differ significantly from those in Western populations28, 29). As PRS-based risk stratification gains traction, it is essential to assess its potential role within the context of Japan’s unique healthcare landscape and public health priorities. This review aimed to synthesize the current evidence surrounding the use of PRSs for ASCVD prevention among the Japanese population and to evaluate its implications for risk prediction, early intervention, and the development of population-specific preventive strategies. In doing so, we seek to inform future research and support responsible implementation of genetic risk profiling in the Japanese context.

2.What are PRSs?

A PRS is constructed by aggregating genotypes across an individual genome. Each genotype is weighted by its corresponding effect size estimated from a GWAS conducted on independent datasets30). The process typically consists of three main steps. First, researchers obtain a list of SNVs and their effect sizes (e.g., β coefficients, which represent the association per allele with the outcome in linear models, or log-odds/log-hazard rations in logistic or Cox models), which quantify the strength of the association of each SNV with the trait of interest. Publicly available GWAS summary statistics, such as those found in the GWAS catalog (https://www.ebi.ac.uk/gwas/), are the primary sources of these data. Second, linkage disequilibrium (LD) clumping was performed to account for LD, that is, non-random association of alleles at different loci. This reduces redundancy between correlated SNVs and separates independently associated signals, thereby improving the interpretability and performance of the PRS. Third, a PRS is calculated by summing the weighted genotypes across the selected SNVs. Various P-value thresholds are often used, with the optimal threshold determined on an independent validation dataset to maximize prediction accuracy.

In recent years, modern PRSs have evolved to incorporate millions of common genetic variants across the genome, in addition to those that exceed strict significance thresholds. Advanced methods that go beyond traditional strict P-value thresholds and LD clumping have been developed, such as Bayesian approaches (e.g., LDpred31), LDpred2 32), LDpred-funct33), PRS-CS34), AnnoPred35), SBayesC36), Bayesian sparse linear mixed models37), PleioPred38), STMGP39)), penalized regression methods (e.g., Lassosum40)), and ensemble or integrative frameworks (e.g., MegaPRS41)). These methods can consider genome-wide variants while controlling noise by considering the LD structure more comprehensively and applying effect size reduction, thereby improving prediction performance.

Currently, large-scale GWAS involving millions of individuals—including those of Japanese and other East Asian ancestries—is underway, gradually capturing a large portion of the heritability that can be explained by common variants, and genome-wide genotyping data can be used to almost completely estimate an individual’s polygenic predisposition21). However, since many large-scale GWAS are based on prevalent cases rather than on incident cases, their ability to predict future disease events needs to be examined26). The majority of current GWAS datasets are derived from populations of European descent, and it is well known that PRSs perform optimally in European populations, while their predictive accuracy decreases in non-European populations42). In recent years, GWAS based on multi-ethnic cohorts has led to the development of PRSs that show improved predictive performance not only in European populations but also in diverse non-European populations such as East Asians and Africans43, 44). These advances demonstrate the potential of more globally applicable risk prediction tools. However, even with such improvements, disparities in predictive accuracy across ancestries remain, highlighting the need to develop PRSs that ensure equitable performance across all ethnic groups and minimize ancestral bias.

Another important consideration is that the choice of the PRS construction method can have a significant impact on individual risk estimates. Various statistical methods, from Bayesian statistical frameworks to penalized regression, can generate different polygenic scores, even when derived from the same GWAS summary statistics45). Variation in PRS output across computational methods can lead to inconsistent risk stratification, especially at the individual level. Thus, the reproducibility and interpretability of polygenic risk estimates must be carefully evaluated, especially in clinical contexts and reproductive applications such as embryo selection, where decision-making may depend on these predictions. Efforts to standardize PRS construction and evaluate consistency across methods are essential to ensure the fair and reliable application in any population.

A PRS represents an individual’s lifelong and immutable susceptibility to disease and functions as an ultimate antecedent marker of risk. However, it cannot determine whether the pathological processes are actively progressing at a given time. Moreover, elevated PRS values often reflect the cumulative effects of multiple overlapping biological pathways that contribute to disease susceptibility, making it difficult to pinpoint the specific mechanisms that drive the onset of disease. This biological complexity has driven the development of pathway-specific PRSs, which aggregate genetic risk within defined biological pathways to enable more mechanistic and targeted risk stratification46, 47). In this context, integrating polygenic risk information with other layers of biological data (e.g., genomics, proteomics, and metabolomics) through multi-omics approaches, is becoming increasingly important for elucidating the underlying pathophysiological mechanisms of complex diseases. These dynamic data layers capture the real-time biological consequences of gene–environment interactions, offering proximal markers of subclinical disease activity. Such integrative analyses not only have the potential to improve the accuracy of disease risk prediction, but may also uncover novel therapeutic targets and more directly connect genetic risk stratification to actionable, personalized prevention, and treatment strategies.

Importantly, because germline genotypes remain unchanged throughout life, PRSs, once generated, are stable across the lifespan. This enables the calculation of polygenic scores at any point in time, including birth, providing a lifelong index of inherited disease susceptibility with a single measurement26). This temporal stability represents a distinct advantage over conventional biomarkers, which may fluctuate over time due to environmental or physiological factors.

3. Current Evidence in Japan

Most studies evaluating PRSs have been conducted in individuals of European ancestry, primarily in cohorts based in Europe and the United States. These studies have shown that PRSs can modestly improve the prediction of incident ASCVD when added to traditional risk factors4). However, evidence supporting the utility of PRSs in Japanese populations remains limited, and its generalizability to non-European populations is yet to be fully established (Table 1).

Table 1.Summary of the association between PRS and atherosclerotic cardiovascular disease in Japanese population

Trait Authors Study Cohort Study Design Total participants Outcome Cases SNP PRS construction Method GWAS Covariate Effect size Prediction ability Reference no.
Hypertension Fujii R, al.et J-MICC Study Cross-sectional study

11,252 PRS

construction: 3,376

Association:7,876

SBP, DBP,

Hypertension

1,254

Hypertension: 30,755

SBP: 37,543

DBP: 24,151

C+T approach

UK Biobank

Biobank Japan

age, sex, BMI,smoking status, alcohol intake,

dietary total energy intake, sedentary time,

top five genetic principal components

The difference (95%CI) of SBP and DBP per SD,

2.56(1.83-3.30) mmHg,

2.53(1.80-3.26)mmHg,respectively

- 49
Takase M, et al.

TMM Comm

Cohort Study

Cross- sectional study

7,027 PRS

construction: 1,405

Association: 5,622

Hypertension

Home hypertension

Hypertension: 2294

Home hypertension: 2,322

SBP:1,786

home SBP: 1,786

C+T approach Biobank Japan

age, sex, top. Six genetic principal components,

measurement seasons (home SBP only)

OR for the highest tertile,

1.69 (1.47-1.96) for hypertension,

1.68 (1.45-1.94) for home hypertension

C statistic, 0.745 (0.732-0.758) for hypertension, 0.746 (0.733-0.758)

for home hypertension (age, sex, top six genetic principal components, seasons,

obesity, drinking, regular physical activity, sodium-to-potassium ratio)

C statistic,0.748 (0.836–0.761) for hypertension, 0.753 (0.740–0.765)

for home hypertension (above model + PRS)

50
Fujii R, et al. J-MICC Study Prospective cohort study 9,296 CVD mortality 41 882,808

PRS-CS

C+T approach

Biobank Japan

age, sex, BMI, smoking, alcohol. Dietary sodium,.

medications for diabetes, medications for dyslipidemia,

top 5 genetic principal components

HR per SD increments in PRS

SBP-PRS HR:1.67 (1.21-2.32)

DBP-PRS HR:1.62 (1.17-2.26)

C statistics: 0.757 for clinical risk factors 0.763 (0.687-0.838)

for clinical + SBP-PRS, 0.761 (0.685-0.836) for clinical + DBP-PRS

52
Diabetes Bui TH, et al. Bunkyo Health Study Cross- sectional study 1,610 Diabetes 126 110 Not shown Biobank Japan

age, BMI, percentage of body fat, subcutaneous fat area,

visceral fat area, and physical activity

OR for the highest tertile,

2.53 (1.69-3.80)

- 55
Inaishi J, et al. Hisayama Study Prospective cohort study 1,465 Diabetes 199 84 Not shown

Biobank Japan, DIAGRAM

Consortium, AGEN-T2D

Consortium, SAT2D

Consortium, MAT2D

Consortium

age, sex, family history of diabetes, hypertension, serum

total cholesterol, serum HDL cholesterol, serum triglycerides,

use of lipid-modifying medication, BMI, smoking habits,

alcohol intake, and regular exercise

HR for the highest quintile,

2.61 (1.67-4.05)

C statistic, 0.818 (0.791-0.845)

(covariate + fasting plasma glucose + 2 hours plasma glucose)

C statistic, 0.823 (0.796-0.850)

(covariate + fasting plasma glucose + 2 hours plasma glucose + GRS)

56
Takase M,et al.

TMM Comm

Cohort Study

Cross- sectional study

9,681

PRS construction: 1,936

Association: 7,745

Diabetes 467 42,845 C+T approach Biobank Japan age, sex, top six genetic principal components

OR for the highest tertile,

3.16 (2.45-4.12)

C statistic, 0.788 (0.769-0.807)

(covariate, smoking, drinking, obesity, GGT, physical activity, family history of diabetes)

C statistic, 0.802 (0.783-0.821)

(above model + PRS)

57
Takase M, et al.

TMM Comm

Cohort Study

Prospective cohort study 11,014 Diabetes 297 66,950 C+T approach Biobank Japan

age, sex, top six genetic

principal components

OR for the highest tertile,

2.31 (1.71-3.15)

C statistic, 0.703 (0.674-0.732)

(covariate, smoking, drinking, obesity, GGT, physical activity, family history of diabetes)

C statistic, 0.719 (0.692-0.747)

(above model + PRS)

58
Hypercholesterolemia Tanisawa K, et al. WASEDA’S Heath Study Cross- sectional study 1,296 Lipids, Diabetes, Hypertension

High TG: 209

High LDL-C: 455

Low HDL- C: 60

Diabetes: 65

Hypertension: 486

LDpred2 TG: 813,267

LDL-C: 813,267

HDL: 813,267

Diabetes: 813,871

Hypertension: 813,267

LDpred2

C+T approach

Biobank Japan

age, sex, BMI, smoking status, alcohol drinking status,

menopause status, history of CVD, history of cancer,

TG-lowering medication use, cholesterol lowering medication use,

antidiabetic medication use, antihypertensive medication use,

and the top 10 genetic principal components

OR per SD increment in PRS

High TG: 2.13 (1.77-2.56)

High LDL-C: 1.74 (1.52 2.56)

Low HDL-C: 2.54 (1.86-3.48)

Diabetes: 2.42 (1.79-3.28)

Hypertension: 1.56 (1.35 1.80)

Proportion of variance Explained by adding PRS

High TG: 0.080

High LDL-C: 0.069

Low HDL-C 0.090

Diabetes: 0.077 Hypertension: 0.027

59
Stroke Hachiya T,et al.

KyusyuU data,

JPJM data

case-control,

nested-case control study

KyushuU: 2,194

JPJM: 672

Ischemic Stroke

KyushuU: 1,097

JPJM: 336

357,367

polyGRS

(Bayesian mixed model)

Biobank Japan, Tohoku Medical Megabank Project,

Japan Public Health Center-based prospective study,

Japan Multi- Institutional Collaborative

Hypertension, diabetes, hyperlipidemia, atrial fibrillation

OR for top vs bottom quintile:

KyushuU 1.75(1.33–2.31),

JPJM 1.99 (1.19–3.33)

ΔC-index: 0.700 (95% CI: 0.679–0.722)

NRI: 0.151 (95% CI: 0.068–0.235)

IDI: 0.004 (95% CI: 0.001–0.006)

66
Hachiya T,et al. Hisayama Study Prospective cohort study 3,038 Ischemic Stroke 91 357,367

GW-PRS

(weighted sum using BLUP

from Japanese GWAS)

Biobank Japan, Tohoku Medical Megabank Project,

Japan Public Health Center-based prospective study,

Japan Multi- Institutional Collaborative

age, sex, hypertension, diabetes, cholesterol,

BMI, ECFG, smoking, alcohol, exercise

HR for the highest quintile,

2.44 (1.16-5.12)

- 67

Abbreviations: CVD, cardiovascular disease; BMI, body mass index; SBP, systolic blood pressure; DBP, diastolic blood pressure; GGT, gamma-glutamyl transferase; ECG, electrocardiogram; PRS, polygenic risk score; SNP, single nucleotide polymorphism; GWAS, genome-wide association study; GRS, genetic risk score; TG, triglycerides; HDL, high-density lipoprotein, LDL, low-density lipoprotein; T2D, type 2 diabetes; HR, hazard ratio; OR, odds ratio; CI, confidence interval; AUC, area under the curve; NRI, net reclassification improvement; IDI, integrated discrimination improvement; BLUP, best linear unbiased prediction.

Hypertension

A recent large-scale GWAS identified over 2,103 loci associated with BP regulation48). The identification of BP-associated variants has enabled the development of a PRS for BP. In Japan, the Japan Multi-institutional Collaborative Cohort (J-MICC) study conducted a cross-sectional analysis and found that participants in the highest PRS quintile had significantly higher systolic and diastolic BP values than those in the middle quintile: 4.55 mmHg (95% confidence interval [CI], 2.26–6.85) and 2.32 mmHg (95% CI, 0.86–3.78), respectively49). Similarly, the Tohoku Medical Megabank Community-based Cohort Study (TMM CommCohort Study) demonstrated that the BP PRS was significantly associated with the prevalence of both clinical and home hypertension, independent of established risk factors such as age, sex, body mass index (BMI), sodium-to-potassium ratio, alcohol consumption, and physical activity50). The addition of the PRS to conventional risk models modestly improved discrimination ability. For hypertension, the C-statistic increased from 0.743 (95% CI, 0.731–0.756) to 0.748 (95% CI, 0.736–0.761); for home hypertension, from 0.749 (95% CI, 0.736–0.761) to 0.753 (95% CI, 0.740–0.765)50).

Although the BP PRS has primarily been studied in relation to hypertension risk, recent studies have extended their application to hard clinical endpoints, including all-cause and cardiovascular mortalities. In a large trans-biobank study involving approximately 676,000 individuals from the BioBank Japan (BBJ), UK Biobank (UKB), and FinnGen, Sakaue et al. demonstrated that the PRS for systolic BP was consistently associated with all-cause mortality across all three cohorts51). Likewise, the PRS for diastolic BP also showed a significant association with mortality in each biobank, indicating that genetic predisposition to elevated BP contributes to increased mortality risk across diverse populations. Additionally, Fujii et al. reported a significant association between the BP PRS and cardiovascular mortality in a Japanese general population52). Although no statistically significant interaction was observed between the PRS and modifiable lifestyle factors, stratified analyses suggested that the attributable risk of smoking for cardiovascular mortality may be greater in individuals with higher PRSs. These findings imply that a genetic predisposition could potentially modify the absolute benefits of behavioral interventions. This highlights an important gap in our understanding of how genetic risk interacts with behavioral interventions to influence long-term outcomes.

The utility of PRSs in predicting the development of hypertension remains unclear. Prior studies have not accounted for baseline systolic or diastolic BP, limiting their interpretability50). To our knowledge, no prospective studies have evaluated the predictive utility of a PRS for hypertension in the Japanese population. Therefore, it remains unclear whether a PRS can predict incident hypertension or improve risk stratification beyond baseline BP measurements. The current analyses yield inconclusive findings, and larger prospective cohort studies are needed to clarify the role of PRSs in this context. The declining cost of genetic testing, coupled with the ability to compute PRSs for multiple diseases from a single biospecimen, has broadened the potential application of PRSs in clinical and public health settings. However, because BP can be measured easily, inexpensively, and non-invasively using standard monitoring devices, the added value and cost-effectiveness of incorporating a PRS into hypertension risk prediction models remain uncertain. Further research is needed to determine whether the PRS provides sufficient incremental predictive utility to justify its implementation in routine practice.

Diabetes

Several monogenic variants associated with diabetes have been identified, including mutations in genes such as Glucokinase, Hepatocyte Nuclear Factor 1-Alpha, and Pancreatic and Duodenal Homeobox1, and those causing mature-onset diabetes in the young53). However, these monogenic forms account for only a small fraction of the overall risk of diabetes. A recent large-scale genome-wide association study involving over 2.5 million individuals identified 1,289 independent association signals across 611 loci54). These signals were categorized into eight distinct clusters based on cardiometabolic traits. Cluster-specific polygenic scores were associated with vascular outcomes such as coronary artery disease and diabetic nephropathy, highlighting the key role of obesity-related mechanisms in the development of diabetes complications54).

Several studies have investigated the association between PRSs and diabetes in Japan. A cross-sectional analysis from the Bunkyo Health Study constructed a genome risk score (GRS) using 110 diabetes-related SNVs. The GRS was based only on variants that had previously reached genome-wide significance (P<5×10⁸) in a Japanese GWAS and therefore differs from polygenic risk scores (PRSs), which typically include genome-wide variants regardless of significance. Despite this more conservative approach, the GRS was significantly associated with the prevalence of diabetes55). The Hisayama Study developed a GRS based on 84 genome-wide significant variants and demonstrated that a higher GRS was associated with an increased risk of developing diabetes, independent of environmental risk factors56). In comparison to individuals in the lowest quintile, those in the highest quintile had a HR of 2.85 (95% CI, 1.83–4.44). Although the association was attenuated after adjusting for fasting blood glucose and 2-hour post-load glucose, it remained significant (HR, 2.05; 95% CI, 1.31–3.21). Similar findings were reported in the TMM CommCohort Study57, 58), which showed that the PRS, lifestyle factors, and family history were independently associated with incident diabetes. Notably, even among participants with an ideal lifestyle and no relevant family history, those with a high genetic risk had an elevated risk of developing diabetes (Odds ratio [OR], 2.76; 95% CI, 1.70–4.63). In contrast, individuals with a family history of diabetes exhibited an increased risk, even when their genetic risk was low and their lifestyle was ideal (OR, 2.97; 95% CI, 1.16–6.70). The predictive performance of diabetes risk models, as measured by the C-statistic (AUROC), improved modestly with the addition of a PRS to models that included lifestyle and family history. The Hisayama Study also reported enhanced discrimination and improved reclassification with the inclusion of a PRS in models incorporating traditional risk factors56). However, the overall improvement in prediction was limited. These findings highlight the potential utility of PRSs in stratifying the risk of diabetes; however, further prospective studies are needed to clarify its role in prevention strategies.

Hypercholesterolemia

Dyslipidemia is a major modifiable risk factor for atherosclerotic cardiovascular disease (ASCVD), and the causative role of elevated LDL cholesterol and triglyceride levels has been well established in epidemiological and genetic studies2). Familial hypercholesterolemia (FH) is a monogenic disease characterized by markedly elevated LDL-C levels and is one of the best-known genetic causes of premature ASCVD2). In recent years, common genetic variants associated with lipid traits have been aggregated into PRSs, which have emerged as additional tools to quantify genetic risk beyond single-gene variants20).

The WASEDA’S Health Study demonstrated that PRS constructed from common variants was significantly associated with a higher prevalence of elevated TG and LDL-C, and low HDL-C levels59). Importantly, the study found that high cardiorespiratory fitness (CRF), assessed by peak oxygen uptake per kilogram of body weight, attenuated the genetic predisposition to TG elevation (P for interaction = 0.001), but not LDL-C or HDL-C. These findings suggest that high CRF may provide a particular benefit in individuals with a high PRS for triglycerides. Tam et al. developed genome-wide PRSs for various lipid traits using data from Biobank Japan and tested the PRS among individuals of Chinese ancestry60). These scores were significantly associated with their respective lipid traits across individuals of different life stages, including children, adolescents, healthy adults, and adult women. Moreover, the PRS predicted the risk of incident dyslipidemia over a 3-year follow-up period. The predictive performance, as measured by the AUROC, modestly improved when PRSs were added to models that included age, sex, BMI, and genetic principal components.

In previous studies, 20% to 30% of patients clinically diagnosed with FH had a high PRS for LDL cholesterol61-64). Notably, individuals in the top 5th percentile of the LDL-C PRS exhibited comparable LDL-C levels to individuals with monogenic FH variants65). A comprehensive assessment of both monogenic and polygenic factors may improve the diagnostic yield beyond that of FH gene panel testing alone. This approach may play an important role in identifying individuals who could benefit from early and intensive lipid-lowering therapy. However, this hypothesis requires confirmation in prospective studies. Future research should explore the utility of lipid and lipoprotein PRSs in guiding therapeutic interventions and clarifying their clinical significance.

Cardiovascular Disease

In Japan, the Iwate Medical Megabank Organization has played a leading role in investigating the genetic and environmental determinants of stroke, and such efforts were initiated relatively early in comparison to other population-based cohorts. Hachiya et al. developed a PRS for ischemic stroke and assessed its ability to improve risk prediction beyond traditional clinical factors66). The PRS was significantly associated with an increased risk of ischemic stroke and its subtypes, including large-vessel disease, small-vessel disease, and cardioembolic stroke, across both case-control and nested case-control study designs. When added to a conventional risk model, including hypertension, diabetes mellitus, hyperlipidemia, and atrial fibrillation, the PRS significantly improved risk discrimination, as indicated by a positive net reclassification index. This association was further confirmed in the Hisayama Study, a prospective population-based cohort study in Japan67) where the PRS was independently associated with incident ischemic stroke. Participants in the highest PRS quintile had a significantly higher risk of ischemic stroke than those in the lowest quintile (HR, 2.43; 95% CI, 1.15–5.12). However, no statistically significant interactions were observed between the PRS and lifestyle factors, suggesting that effective management of modifiable risk factors is essential, regardless of genetic predisposition.

In the GIGASTROKE consortium, a large-scale meta-analysis involving over 2.5 million individuals, 61 novel stroke-associated loci were identified68). This study also developed a composite PRS integrating genetic contributions not only from stroke-related loci but also from traits such as BP, BMI, and atrial fibrillation. These associations were consistently observed in both East Asian and European populations. Building on this work, Fujii et al. recently constructed a multi-trait PRS that combines genetic risk scores for systolic BP, BMI, triglycerides, LDL cholesterol, estimated glomerular filtration rate, and HbA1c. This multi-trait PRS was associated with CVD mortality independently of conventional risk factors69). In comparison to individuals in the bottom 90%, those in the top 10% of the multi-trait PRS distribution had a 32% higher risk of all-cause mortality and a 163% higher risk of CVD-related mortality. These findings suggest that a comprehensive evaluation of genetic risk for multiple risk factors may enable more precise stratification of ASCVD risk. In the future, it will be necessary to develop frameworks that utilize such trait PRSs to identify high-risk individuals and to implement appropriate primary prevention strategies at an early stage. Moreover, prospective interventional studies are needed to evaluate the effectiveness of preventive interventions in high-risk populations.

4.Practical Challenge for the Implementation of PRSs in Japan

The ultimate goals of implementing PRSs in clinical and public health settings are to prevent disease and identify at-risk individuals early in life. However, several important limitations must be addressed before PRSs can be widely adopted in clinical or public health practice.

According to a scientific statement from the AHA4), the following three broad criteria should be considered before the implementation of PRSs: 1) efficacy, 2) harm, and 3) logistics.

The AHA suggested that the clinical efficacy of a PRS is likely appropriate when either of the following is achieved: 1) the integration of a PRS into clinical risk tools substantially improves their accuracy, and 2) PRS risk tools can identify participants at risk to a degree that is at least equivalent to that of individuals with monogenic risk variants4).

First, regarding efficacy, the addition of PRSs to established clinical risk models has been shown to improve predictive accuracy for complex diseases such as coronary heart disease, diabetes, and atrial fibrillation, primarily in European populations70). However, evidence in Asian populations remains limited, and further studies are needed to validate the clinical utility of PRSs in these groups. In addition, it remains unclear whether early life screening using PRSs alone can effectively identify individuals with a lifetime risk comparable to that of monogenic variant carriers and guide the timely initiation of preventive interventions. Currently, there is no established prevention framework for the early identification of individuals at high polygenic risk. Integrating multi-omics data, such as metabolomics, proteomics, and epigenomics, may help to elucidate the early biological changes associated with the onset of disease in these individuals and uncover actionable targets for intervention. Such insights could ultimately pave the way for precision prevention strategies based on both genetic and molecular profiles.

Similarly, for preventive intervention trials, targeting high-risk individuals enables the design of studies with greater statistical power, using smaller cohorts and shorter follow-up periods. By enriching the study population with individuals with a higher baseline risk, the ability to detect the effects of preventive treatments, such as pharmacological therapies or lifestyle interventions, is substantially enhanced. Therefore, early risk stratification using PRSs is expected to play a pivotal role in streamlining observational and interventional research efforts, even in the absence of fully established preventive measures. However, it remains uncertain whether knowledge of an individual’s genetic influence on PRSs can lead to preventive actions. For example, the GeneRISK study reported that 42.6% of individuals with a high polygenic and clinical risk of ASCVD undertook at least one health-promoting behavior, including visiting a doctor or losing weight, and these behavioral changes were independently associated with both the PRS and clinical risk levels71). In contrast, the MI-GENES randomized trial showed that disclosure of a CHD genetic risk score led to improved LDL-C levels and higher statin use but did not result in measurable changes in diet or physical activity72). Other trials, such as the P5 Study and GC/LC Study, highlighted modest motivational effects, but no consistent impact on actual health behavior or program attendance73, 74). Further research is needed to determine whether risk prediction improves and whether disclosing a PRS improves health-related behaviors. It is also crucial to recognize that a high polygenic risk score does not necessarily correspond to a single pathogenic mechanism.

Second, although concerns regarding racial disparities in healthcare have been central to discussions on PRS implementation in Western countries, different challenges are anticipated in Japan. In Japan, where the population is more genetically homogeneous than Western multi-ancestry populations, the major concerns may be related to disparities in socioeconomic status, geographic location, and health literacy rather than ancestry. Access to PRS testing may be limited to those with a higher socioeconomic status or those living in urban areas with specialized medical facilities, potentially leading to increased health disparities. Furthermore, subtle but significant genetic heterogeneity exists within Japan, which may affect the accuracy and transferability of PRSs75-77). These considerations highlight the need for careful validation of PRSs across diverse regional populations within Japan, and for the development of equitable frameworks to ensure fair access and appropriate interpretation.

Third, several logistical and educational challenges need to be addressed. Currently, the genomic data required for PRS calculation are primarily generated through research initiatives or direct-to-consumer testing services and are largely external to the clinical care setting26). The lack of systematic integration of genomic data into electronic health records limits the ability to leverage PRSs in routine CVD assessments. Moreover, germline genotypes remain unchanged throughout life, and the interpretation of genetic variants continues to evolve with scientific advances and clinical insights, requiring information technology systems that can flexibly update algorithms and revise decision-support tools accordingly. Limited genetic literacy among clinicians and patients further complicates the appropriate understanding and use of PRSs, posing a risk of misinterpretation and inappropriate risk communication26). In this context, the development of personalized risk assessment tools that integrate PRSs with conventional risk factors in a user-friendly and comprehensible manner is essential to support both clinical decision-making and patient understanding. Healthcare providers and genetic counselors will require targeted education to facilitate an accurate explanation of the PRS results, their limitations, and appropriate clinical applications. Furthermore, clear guidelines are required regarding how PRS results should be communicated, including whether risks are best presented as continuous scores, stratified risk categories (e.g., low, intermediate, high), or both, and how they should be combined with traditional risk factors for treatment recommendations26, 71). Additionally, a shortage of clinical geneticists and genetic counselors is another barrier to providing comprehensive genetic risk counseling at the scale, as is the lack of a regulatory and ethical framework for clinical use, including standards for informed consent, data management, and actionable thresholds. The implementation of PRS-guided care would require substantial investments in genomic infrastructure, health information systems, and provider education, raising concerns about disparities between well-resourced and underresourced institutions. To maximize clinical benefits and minimize unintended disparities, future studies should aim to establish equitable systems for the clinical application of PRSs that are adaptable to the evolving genomic landscape.

Conclusions

PRSs have emerged as promising tools for improving risk stratification for ASCVD by capturing cumulative genetic susceptibility not reflected in traditional clinical factors or family history. Although incorporating PRSs into clinical risk models has led to modest improvements in prediction—particularly among individuals of European ancestry—validation in Asian populations, including Japan, remains limited. Encouragingly, large-scale multi-ethnic initiatives such as the All of Us Research Program78, 79), Our Future Health80), and national efforts like BBJ81) are beginning to address these critical evidence gaps. To ensure successful clinical implementation, it will be essential to overcome practical challenges, including education, data infrastructure, and ethical governance. Ensuring equitable access to PRS-based care is also vital to avoid exacerbating existing health disparities. As genomic testing becomes more accessible, future clinical guidelines should aim to identify populations that are most likely to benefit from PRS-informed decision-making, thereby advancing the broader goal of precision prevention in ASCVD.

Acknowledgements

This work was supported by grants from the Tohoku Medical Megabank Project of the Ministry of Education, Culture, Sports, Science, and Technology (MEXT); the Japan Agency for Medical Research and Development (AMED; JP22tm0124005); and Grants-in-Aid for Scientific Research (KAKENHI #24K02699 to A.H., KAKENHI #24K23673 to M.T., and KAKENHI #25K20591 to M. T.).

The authors are grateful to Nakaya Naoki, Mana Kogure, Rieko Hatanaka, Kumi Nakaya, Ippei Chiba, Sayuri Tokioka, Akira Narita, Taku Obara, Mami Ishikuro, Hisashi Ohseto, Ippei Takahashi, Tomoko Kobayashi, Eiichi N Kodama, Yohei Hamanaka, Masatsugu Orui, Soichi Ogishima, Satoshi Nagaie, Nobuo Fuse, Junichi Sugawara, Shinichi Kuriyama, Biobank Japan Project; Koichi Matsuda, Yoko Izumi, Kengo Kinoshita, Gen Tamiya, Masayuki Yamamoto and the members of the Tohoku Medical Megabank Organization, including the Genome Medical Research Coordinators, and the office and administrative personnel for their assistance. A complete list of members is available at https://www.megabank.tohoku.ac.jp/english/a240901/. The authors also thank the Japan Atherosclerosis Society, the Asian-Pacific Society of Atherosclerosis and Vascular Diseases, and the Editorial Board of the Journal of Atherosclerosis and Thrombosis for providing the opportunity to write this article.

Competing Interests

There are no competing interests.

References
 

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