Power analyses for our family-based tests were conducted in PBAT by identifying the family configurations and CD affection status of the study sample. Assumptions included: (1) population prevalence of disease = 0.1; (2) α = 0.05; (3) an A-allele frequency of 0.53; and (4) disease locus = marker locus. Power is shown in Table 3 (lower half) for various odds ratios (Odds ratio point estimate and lower and upper bound of 95% confidence interval from Dick et al., 2006)) and models of inheritance (i.e. dominant, recessive).
