Required sample size for the detection of pleiotropy varies with the detectable effect size and prevalence rates of comorbid disorders. Figure 1c shows the required sample size by effect size of the diplotype and the comorbid disorder when power is fixed at 80%. For example, a sample size of 1,378 is needed to detect an OR of 1.60 with 92% power, while a sample size of 1,806 is needed to detect an OR of 1.80 with 84% power.
