Incorporating contextual information into KGWAS for interpretable GWAS discovery
Organizations: University of Michigan · gRED, Genentech · Stanford University
Abstract
Genome-Wide Association Studies (GWAS) identify associations between genetic variants and disease; however, moving beyond associations to causal mechanisms is critical for therapeutic target prioritization. The recently proposed Knowledge Graph GWAS (KGWAS) framework addresses this challenge by linking genetic variants to downstream gene-gene interactions via a knowledge graph (KG), thereby improving detection power and providing mechanistic insights. However, the original KGWAS implementation relies on a large general-purpose KG, which can introduce spurious correlations. We hypothesize that cell-type specific KGs from disease-relevant cell types will better support disease mechanism discovery. Here, we show that the general-purpose KG in KGWAS can be substantially pruned with no loss of statistical power on downstream tasks, and that performance further improves by incorporating gene-gene relationships derived from perturb-seq data. Importantly, using a sparse, context-specific KG from direct perturb-seq evidence yields more consistent and biologically robust disease-critical networks.
Figures & tables
| Small cohort sample size | |||||||
| # Edges | 1,000 | 2,500 | 5,000 | 7,500 | 10,000 | 50,000 | |
| GWAS | 0 | 14 | 15 | 29 | 36 | 49 | 201 |
| KGWAS | 12.1M | 27.00 (1.00) | 24.67 (1.53) | 37.67 (2.08) | 55.00 (1.73) | 62.33 (2.52) | 221.00 (4.36) |
| + Remove gene programs | 12.1M | 26.33 (1.53) | 24.00 (2.65) | 36.33 (1.53) | 53.33 (2.31) | 65.33 (2.08) | 220.00 (4.36) |
| + Prune edge types | 3.4M | 25.67 (3.06) | 26.33 (2.52) | 46.33 (2.52) | 58.33 (2.52) | 67.33 (3.51) | 221.00 (2.00) |
| + Collapse GG edges | 2.3M | 25.67 (3.06) | 26.00 (2.00) | 46.33 (0.58) | 55.00 (2.65) | 66.67 (1.53) | 218.67 (2.52) |
| Small cohort sample size | |||||||
|---|---|---|---|---|---|---|---|
| # Edges | 1,000 | 2,500 | 5,000 | 7,500 | 10,000 | 50,000 | |
| Context-aware KGWAS ( ) | 625K | 30.67 (2.31) | 34.67 (4.04) | 53.00 (2.00) | 58.33 (2.08) | 79.67 (2.08) | 229.00 (3.61) |
| with randomized G2G | 863K | 24.67 (2.31) | 27.33 (1.53) | 47.33 (2.08) | 54.33 (1.15) | 67.33 (4.73) | 221.33 (3.06) |
| with dropped G2G | 747K | 27.67 (2.52) | 29.67 (0.58) | 38.33 (2.31) | 51.00 (1.73) | 72.00 (2.00) | 224.33 (4.73) |
| with randomized V2G and G2G | 863K | 19.67 (1.15) | 26.33 (4.93) | 43.00 (12.74) | 50.67 (1.52) | 61.67 (5.69) | 211.00 (3.00) |
Biomedical KGs
Biomedical knowledge graphs organize evidence about genes, diseases, drugs, pathways, and patients for computational discovery and clinical reasoning.
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