GRN and Alzheimer disease: The GRN rs5848 TT genotype is associated with reduced progranulin levels in FTD and AD (Rademakers et al., 2008; Hsiung et al., 2011) and has been described as risk factor for neurodegenerative diseases (Rademakers et al., 2008; Chen et al., 2015; Xu et al., 2017).