Evidence map›Paper›PMID 39168121›Full record

ArticleAmerican journal of human genetics2024

Inflation of polygenic risk scores caused by sample overlap and relatedness: Examples of a major risk of bias.

Colin A Ellis, Karen L Oliver, Rebekah V Harris, Ruth Ottman, Ingrid E Scheffer, Heather C Mefford, Michael P Epstein, Samuel F Berkovic, Melanie Bahlo

Abstract read
In one paragraph

Article in American journal of human genetics, 2024. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 16 papers.

0numbers the graph read from it
0cells of the map it votes in
16citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

16 citing papers in PubMed.

  1. Review
  2. Stratification by a polygenic risk score of common variation aids in Alzheimer's disease rare variant discovery.Alzheimer's & dementia : the journal of the Alzheimer's Association · 2026
    Observational
  3. Cross-ancestry polygenic risk scores enhance Alzheimer's disease risk prediction in multiethnic cohorts.Alzheimer's & dementia : the journal of the Alzheimer's Association · 2026
    Article
  4. Review
  5. Polygenic scores as modifiers in Mendelian diseases.Medizinische Genetik : Mitteilungsblatt des Berufsverbandes Medizinische Genetik e.V · 2026
    Article
  6. Article
  7. Review
  8. Article
  9. Article
  10. Methods for modeling gene-environment interplay using polygenic risk scores.Statistical applications in genetics and molecular biology · 2026
    Review
  11. The role of genomic-informed risk assessments in predicting dementia outcomes.Alzheimer's & dementia : the journal of the Alzheimer's Association · 2025
    Article
  12. Article
  13. The Role of Genomic-Informed Risk Assessments in Predicting Dementia Outcomes.medRxiv : the preprint server for health sciences · 2025
    Article
  14. Article
  15. Article
  16. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

9 authors.

Colin A EllisDepartment of Neurology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.
Karen L OliverEpilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC 3084, Australia; Population Health and Immunity Division, the Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC 3052, Australia.
Rebekah V HarrisEpilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC 3084, Australia.
Ruth OttmanDepartments of Neurology and Epidemiology, and the Gertrude H. Sergievsky Center, Columbia University Irving Medical Center, New York, NY 10032, USA; Division of Translational Epidemiology and Mental Health Equity, New York State Psychiatric Institute, New York, NY 10032, USA.
Ingrid E SchefferEpilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC 3084, Australia; Department of Paediatrics, Royal Children's Hospital, University of Melbourne, Parkville, VIC 3052, Australia; The Florey Institute and Murdoch Children's Research Institute, Parkville, VIC 3052, Australia.
Heather C MeffordCenter for Pediatric Neurological Disease Research, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
Michael P EpsteinDepartment of Human Genetics, Emory University School of Medicine, Atlanta, GA 30307, USA.
Samuel F BerkovicEpilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC 3084, Australia.
Melanie BahloPopulation Health and Immunity Division, the Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC 3052, Australia. Electronic address: bahlo@wehi.edu.au.

Funding

Polygenic risk in familial epilepsyK23NS121520 · NINDS · UNIVERSITY OF PENNSYLVANIA · PI ELLIS, COLIN · 2021 to 2025
$1.1M
NINDS NIH HHS K23 NS121520
6 · The paper itself

Abstract

Polygenic risk scores (PRSs) are an important tool for understanding the role of common genetic variants in human disease. Standard best practices recommend that PRSs be analyzed in cohorts that are independent of the genome-wide association study (GWAS) used to derive the scores without sample overlap or relatedness between the two cohorts. However, identifying sample overlap and relatedness can be challenging in an era of GWASs performed by large biobanks and international research consortia. Although most genomics researchers are aware of best practices and theoretical concerns about sample overlap and relatedness between GWAS and PRS cohorts, the prevailing assumption is that the risk of bias is small for very large GWASs. Here, we present two real-world examples demonstrating that sample overlap and relatedness is not a minor or theoretical concern but an important potential source of bias in PRS studies. Using a recently developed statistical adjustment tool, we found that excluding overlapping and related samples was equal to or more powerful than adjusting for overlap bias. Our goal is to make genomics researchers aware of the magnitude of risk of bias from sample overlap and relatedness and to highlight the need for mitigation tools, including independent validation cohorts in PRS studies, continued development of statistical adjustment methods, and tools for researchers to test their cohorts for overlap and relatedness with GWAS cohorts without sharing individual-level data.

Indexed as

BiasGenetic Predisposition to DiseaseGenome-Wide Association StudyMultifactorial InheritanceCohort StudiesFemaleGenetic Risk ScoreHumansPolymorphism, Single NucleotideRisk Factors

Identifiers

PMID39168121
PMCPMC11393675

What OpenQuestion holds

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.