Table 3.
Parallel analytic issues in GWAS and EWAS.
| GWAS | EWAS | ||
|---|---|---|---|
| Individual-level (top-down) | Neighborhood-level (bottom-up) | ||
| Agnostic to associations | Yes | Yes | Yes |
| Alpha error due to large number of predictors | Yes | Yes | Yes |
| Replication of associations | Required | Required | Challenging |
| Linkage of risk makers | Genetic linkage | Marker collinearity | Marker collinearity |
| Attributable risk fraction | Small | Varies | Varies |
| Time variations | No | Yes | Yes |
| Locus of variants | Well-defined | Challenging | Challenging |
| Marker types | Homogeneous | Heterogeneous | Heterogeneous |