GhostKnockoff Inference Empowers Identification of Putative Causal Variants in Genome-wide Association Studies
Overview
Authors
Affiliations
Recent advances in genome sequencing and imputation technologies provide an exciting opportunity to comprehensively study the contribution of genetic variants to complex phenotypes. However, our ability to translate genetic discoveries into mechanistic insights remains limited at this point. In this paper, we propose an efficient knockoff-based method, GhostKnockoff, for genome-wide association studies (GWAS) that leads to improved power and ability to prioritize putative causal variants relative to conventional GWAS approaches. The method requires only Z-scores from conventional GWAS and hence can be easily applied to enhance existing and future studies. The method can also be applied to meta-analysis of multiple GWAS allowing for arbitrary sample overlap. We demonstrate its performance using empirical simulations and two applications: (1) a meta-analysis for Alzheimer's disease comprising nine overlapping large-scale GWAS, whole-exome and whole-genome sequencing studies and (2) analysis of 1403 binary phenotypes from the UK Biobank data in 408,961 samples of European ancestry. Our results demonstrate that GhostKnockoff can identify putatively functional variants with weaker statistical effects that are missed by conventional association tests.
Zhang X, Wang L, Zhao J, Zhao H bioRxiv. 2025; .
PMID: 39974930 PMC: 11838583. DOI: 10.1101/2025.02.05.636660.
Alzheimer's Disease Sequencing Project Release 4 Whole Genome Sequencing Dataset.
Leung Y, Lee W, Kuzma A, Nicaretta H, Valladares O, Gangadharan P medRxiv. 2024; .
PMID: 39677464 PMC: 11643159. DOI: 10.1101/2024.12.03.24317000.
Local genetic correlation via knockoffs reduces confounding due to cross-trait assortative mating.
Ma S, Wang F, Border R, Buxbaum J, Zaitlen N, Ionita-Laza I Am J Hum Genet. 2024; 111(12):2839-2848.
PMID: 39547235 PMC: 11639086. DOI: 10.1016/j.ajhg.2024.10.012.
Second-order group knockoffs with applications to genome-wide association studies.
Chu B, Gu J, Chen Z, Morrison T, Candes E, He Z Bioinformatics. 2024; 40(10).
PMID: 39340798 PMC: 11639161. DOI: 10.1093/bioinformatics/btae580.
Summary statistics knockoffs inference with family-wise error rate control.
Yu C, Gu J, Chen Z, He Z Biometrics. 2024; 80(3).
PMID: 39222026 PMC: 11367731. DOI: 10.1093/biomtc/ujae082.