Table 2.
Example Haplotype Frequencies and Calculation of the Marker Risk Ratio in Unexposed and Exposed Subjects
| Pr(D,M|X = 0) | D = 0 | D = 1 | Total | Pr(Y = 1,D,M|X = 0) | D = 0 | D = 1 | Total | RR(M|X = 0) |
|---|---|---|---|---|---|---|---|---|
| Unexposed | ||||||||
| M = 0 | 0.9 | 0 | 0.9 | 0.9 | 0 | 0.9 | 0.9/0.9 = 1 | |
| M = 1 | 0.05 | 0.05 | 0.1 | 0.05 | 0.1 | 0.15 | 0.15/0.1 = 1.5 | |
| Exposed | ||||||||
| M = 0 | 0.9 | 0 | 0.9 | 0.9 | 0 | 0.9 | 0.9/0.9 = 1 | |
| M = 1 | 0.05 | 0.075 | 0.125 | 0.05 | 0.15 | 0.2 | 0.2/0.125 = 1.6 | |
Abbreviations are as follows: D, allele at causal variant; M, allele at marker locus. Risk ratio (RR) of D = 1 is 2 on disease Y and 1.5 on exposure X. Pr(Y = 1,D,M|X) are relative to baselines that cancel in the marker risk ratio; see Appendix A for details of calculations.