“…However, the use of this method is limited in practice, because
the common risk factors shared by the trait and covariates are often not identified
or measured in GWAS. In recent years, joint analytic methods of multiple traits,
either using individual data or GWAS summary statistics of single traits, have been
developed (Bhattacharjee et al, 2012; Chung, Yang, Li, Gelernter, & Zhao, 2014;
Cotsapas et al, 2011; Hackinger & Zeggini, 2017; Huang, Johnson, & O’Donnell, 2011; Solovieff et al, 2013; Turley et al, 2018; Zhu
et al, 2015). These multi-trait methods can gain substantial statistical
power in certain situations, in particular in the presence of pleiotropy.…”