TABLE 6.

Power of the association test based on the statistic T^gene assuming two interacting disease loci within one gene under different sample sizes and different simulation schemes

		MS program		LD based (r2 = 0.9)
Disease model	(BL, GE)	n = 200	n = 400	n = 200	n = 400
Model 1	(1, 0.7)	0.379 (0.160)	0.564 (0.385)	0.816 (0.709)	0.994 (0.822)
	(1, 0.9)	0.708 (0.272)	0.874 (0.595)	0.909 (0.817)	1.000 (0.827)
Model 2	(1, 0.7)	0.269 (0.152)	0.455 (0.387)	0.468 (0.349)	0.835 (0.641)
	(1, 0.9)	0.458 (0.232)	0.658 (0.559)	0.621 (0.426)	0.938 (0.733)

The power for the single SNP analysis is given in parentheses. BL, baseline effect; GE, genotypic effect. For the MS program, we set the fourth and ninth SNPs as the two interacting loci. For the LD-based simulation, we simulate two LD blocks, one containing six SNPs and the other containing four SNPs, with pairwise r² = 0.9 for SNPs within each block. Two interacting disease loci are from each block with allele frequency P_D = 0.3. The significance level is 0.05. Models 1 and 2 are defined in Table 3.