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. 2015 May 12;44(4):1429–1441. doi: 10.1093/ije/dyv041

Table 1.

Power of EWAS twin and case-control designs

Diff n = 10
 n = 15
 n = 20
 n = 25
 n = 30
 n = 50
TWIN
 CACO
 TWIN
 CACO
 TWIN
 CACO
 TWIN
 CACO
 TWIN
 CACO
 TWIN
 CACO
P < 0.05 P < 10−6 P < 0.05 P < 10−6 P < 0.05 P < 10−6 P < 0.05 P < 10−6 P < 0.05 P < 10−6 P < 0.05 P < 10−6 P < 0.05 P < 10−6 P < 0.05 P < 10−6 P < 0.05 P < 10−6 P < 0.05 P < 10−6 P < 0.05 P < 10−6 P < 0.05 P < 10−6
1% 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
2% 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
3% 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
4% 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2.9 0 0 0
5% 0 0 0 0 0.1 0 0 0 0.2 0 0.1 0 1.4 0 0 0 4.4 0 0 0 56.0 0 9.7 0
6% 0.3 0 0 0 1.5 0 0.1 0 6.7 0 0.6 0 16.1 0 1.1 0 35.2 0 3.5 0 99.3 0 85.3 0
7% 1.9 0 0.3 0 6.7 0 0.6 0 26.1 0 3.7 0 54.2 0 15.4 0 79.0 0 37.7 0 100 0 99.9 0
8% 5.0 0 0.8 0 23.1 0 3.9 0 54.1 0 17 0 82.5 0 45.3 0 98.6 0 80.8 0 100 0 100 0
9% 13.5 0 2.2 0 46.2 0 12.7 0 80.4 0 47.1 0 97 0 85.1 0 100 0 99.4 0 100 0.1 100 0
10% 24.7 0 8.4 0 69.5 0 36 0 94.8 0 80.1 0 100 0 98.4 0 100 0 100 0 100 0.1 100 0
12% 58.0 0 31.4 0 94.0 0 83.6 0 99.8 0 99.5 0 100 0 100 0 100 0 100 0 100 4.8 100 0.6
14% 84.8 0 66.8 0 99.7 0 99 0 100 0 100 0 100 0.1 100 0 100 0.9 100 0.1 100 55.0 100 25.6
16% 95.5 0 83.3 0 100 0 100 0 100 0.2 100 0 100 1.7 100 0 100 7.4 100 0.3 100 99.9 100 70
18% 99.0 0 97.6 0 100 0 100 0 100 0.7 100 0.1 100 8.4 100 0.3 100 30.4 100 6.8 100 100 100 99.5
20% 99.5 0 99.9 0 100 0.1 100 0.1 100 2.8 100 1.2 100 16.8 100 10.3 100 55.8 100 42.5 100 100 100 100
25% 100 0 100 0.1 100 3.8 100 4 100 34.9 100 38.8 100 86.5 100 90.5 100 99.3 100 99.4 100 100 100 100
30% 100 0.5 100 3 100 25.2 100 38.6 100 86.8 100 94.6 100 100 100 100 100 100 100 100 100 100 100 100
30% 100 1.8 100 13.2 100 50.5 100 81.7 100 97.6 100 100 100 100 100 100 100 100 100 100 100 100 100 100
55% 100 11.7 100 52.7 100 82.2 100 99.6 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100
60% 100 57.6 100 98.4 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

Diff, mean methylation difference between affected and unaffected individuals; n, sample size (twin pairs or pairs of cases and controls), TWIN, discordant MZ twin design (paired t test); CACO, case-control design (two-sample t test).