Table 1.
Penetrance table for two-locus additive, threshold and epistasis model
| Xj=0 | Xj=1 | Xj=2 | |
|---|---|---|---|
| Additive | |||
| Xi=0 | η | η (1+θ) | η (1+2θ) |
| Xi=1 | η (1+θ) | η (1+2θ) | η (1+3θ) |
| Xi=2 | η (1+2θ) | η (1+3θ) | η (1+4θ) |
| Threshold | Xj=0 | Xj=1 | Xj=2 |
| Xi=0 | η | η | η |
| Xi=1 | η | η (1+θ) | η (1+θ) |
| Xi=2 | η | η (1+θ) | η (1+θ) |
| Epistasis | Xj=0 | Xj=1 | Xj=2 |
| Xi=0 | η | η | η (1+4θ) |
| Xi=1 | η | η (1+2θ) | η |
| Xi=2 | η (1+4θ) | η | η |
The genotypes at the two loci (i and j) are encoded as the number of risk alleles. The penetrance of each entry is represented by a baseline η and an effect size θ.