“…The third category is the likelihood‐based association tests such as the conditional likelihood method (Schaid & Sommer,1993, 1994), the partial likelihood method for detecting imprinting and maternal effects (Han et al, 2013; Yang & Lin, 2013), the log‐linear models (Vermeulen et al, 2009; Weinberg & Umbach, 2005; Weinberg,1999a, 1999b; Wilcox et al, 1998), and the association test in the presence of informative missingness (Allen et al, 2003). The final category is the mixed effect models (Clark et al, 2016) or regression‐based unified methods combining triads and unrelated subjects (Cordell & Clayton, 2002; Cordell et al, 2004; Epstein et al, 2005; Nagelkerke et al, 2004). Extensions of family‐based methods have also been made for investigating the complex interplay between child and maternal genes, environmental exposures, and lifestyle factors by the inclusion of maternal and fetal genes, environmental factors, and/or their interactions (Kistner et al, 2009; Sinsheimer et al, 2003).…”