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Abstract: TH-OR035

Improving Polygenic Risk Prediction of Kidney Function by Removing Biomarker-Specific Genetics

Session Information

Category: Genetic Diseases of the Kidneys

  • 1202 Genetic Diseases of the Kidneys: Complex Kidney Traits

Authors

  • Du, Jiawen, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
  • Sun, Quan, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States
  • Zhou, Laura Y, Indiana University School of Medicine, Indianapolis, Indiana, United States
  • Franceschini, Nora, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
  • Cox, Nancy Jean, Vanderbilt University Medical Center, Nashville, Tennessee, United States
  • Li, Yun, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
  • Shuey, Megan, Vanderbilt University Medical Center, Nashville, Tennessee, United States
Background

Current eGFR equations using creatinine and/or cystatin-C (eGFRcys, eGFRcr2021, eGFRcr2009, eGFRcr-cys2021, eGFRcr-cys2012) show substantial variability. These discrepancies may arise from underlying biomarker-specific genetics that reflect variation in biomarkers’ basal levels independent of renal function. We hypothesize that using shared genetic architecture can remove biomarker-specific genetic predictors and improve genetic prediction of renal function.

Methods

We split UKB Europeans without kidney disease (N=441K) into training (N=350K) and testing (N=91K) for polygenic risk scores (PRS) development. Using LOGODetect we identified ~17.7K HapMap3 variants in 278 shared genetic regions between eGFRcr and eGFRcys in the training set. We constructed 3 PRSs using PRS-CS: (1) shared PRS, from shared variants (m=18K), (2) biomarker-specific PRS, from variants outside shared regions and excluding LD buddies (R2 > 0.8) (m = 1M), and (3) benchmark PRS, from all variants (m=1.1M). These PRSs were evaluated for eGFR prediction in testing set and UKB participants of African ancestry (N=9K). Replications were performed in an independent cohort, BioVU.

Results

Variants from shared regions show up to 57% higher -log10 p-value correlation among the 5 eGFR GWAS. The shared PRS explains 60% more variance of eGFRcr. The variance explained was lower in eGFRcys (37.4% of benchmark PRS R2), likely due to greater extrarenal influences on this estimate. This was supported by including BMI as one of these influences. Specifically, the shared PRS R2 for eGFRcys increased by 1.7%, while benchmark PRS R2 decreased by 4.3%; creatine-derived estimates were not impacted. In UKB AFR, the shared PRS derived from European yielded 49% higher R2 increment for eGFRcr than the benchmark PRS, and incredibly, the shared PRS demonstrated equal power to benchmark PRS for eGFRcr-cys and 80% of its power for eGFRcys. Validation in BioVU confirmed that shared PRS outperformed the benchmark with 5.2% R2 improvement to eGFRcr.

Conclusion

By including only variants from shared genetic regions, we demonstrated comparable or superior performance to genome-wide PRS in European and African ancestry cohorts. These results highlight the importance of considering biomarker-specific genetics and the potential to improve cross-population genetic prediction of renal function.

Funding

  • Other NIH Support

Digital Object Identifier (DOI)