Response profiles of classes identified in 2- to 4-class models are summarized in Table 2 and in Fig. 1. In the 2-class model, the first class (labeled as the null) included 90.35% of SNPs, and its response profile was characterized by weak associations, indexed by the low means of class indicators, which are −log10(p), for all three phenotypes, indicating that SNPs in this class were not associated with any of included phenotypes. The second class included 9.7% of SNPs and was labeled as the Signal class because its response profile was characterized by relatively stronger overall associations, indexed by higher means of class indicators compared to the null class. In the 3-class model, the three classes were labeled as the Null, AD+ASP, and MD classes, respectively based on their response profiles. The null class was the largest (85.57% of SNPs) and had a profile characterized by relatively low means of class indicators for all three phenotypes. The AD+ASP class consisted of 7.63% of SNPs, and its response profile indicated higher means for AD and ASP, indicating relatively stronger associations with
