Figure 3
From: Sibship T2association tests of complex diseases for tightly linked markers
Power curves of T H and T G at a significance level α = 0.05 using a quadric-allelic marker H 1 , when P ( H 11 ) = P ( H 12 ) = 0.35, P ( H 13 ) = P ( H 14 ) = 0.15 P D = 0.15 and N = 200 sib-pairs for the first set of parameters of the four genetic models of Table 4. Delta_11 = Δ11 = P(H11D) - P(H11)P D is a measure of linkage disequilibrium (LD) between marker H1 and disease locus D. In addition, Δ12 = -Δ11, Δ13 = -Δ14 = Δ11/2. The simulated power curves of ST H and ST G are calculated using combinations of both sib-pairs and sibships of size 3: the number of sib-pairs is equal to N/2 = 100; the number of sibships of size 3 is N/2 = 100; in each of N/4 = 50 sibships of size 3, one is affected and the other two are normal; in the remaining N/4 = 50 sibships of size 3, two are affected and the other one is normal.