These modules estimate the power to detect an interaction between 2 SNPs using an odds ratio (OR) test or logistic regression in population-based samples. The OR test is based on the analysis of interaction in contingency tables.
Standard parameters, such as disease prevalence, allele frequencies, genotype realtive risk (GRR) for the main effect of each locus and GRR for the interaction between the two loci. The 1i calculator takes as a simpler GRR input, with only one parameter for the interaction between the two loci - this corresponds to the interaction between the addive components of each locus. The 4i calculator allows the user to input 2 GRRs for the main effect of each locus (for the additive and dominant components) and 4 GRRs for the interaction, corresponding to the add*add, add*dom, dom*add and dom*dom components. See the reference section for more details on the models.
In addition to expected two-locus genotype penetrances, GRR and odds ratio (OR), the output includes the P-value for both association and epistasis testing plus power for the specified sample size and type-I error rate (alpha).
Have a look at the reference section for details on the input values for this calculator.