GRN and early-onset autosomal dominant Alzheimer disease: GRN gene mutations were found to cause frontotemporal dementia (Baker et al., 2006; Cruts et al., 2006) and have been associated with other neurodegenerative diseases, such as Parkinson’s disease, Creutzfeldt-Jakob disease, motor neuron disease, and Alzheimer’s disease (Baker and Manuelidis, 2003; Lopez de Munain et al., 2008; Malaspina et al., 2001; Vercellino et al., 2011).