TM7SF2 and skeletal dysplasia: However, both LBR and Tm7sf2 have 3beta-hydroxysterol Delta(14)-reductase activity (Silve et al., 1998; Bennati et al., 2006), and this activity was suggested to be important for the pathophysiology of Greenberg skeletal dysplasia caused by LBR mutations (Waterham et al., 2003).