However, in a small cohort of 5 MAPT mutation and 3 GRN mutation carriers who converted from asymptomatic to symptomatic phase, extensive temporal and frontal cortical atrophy were observed, while no gray matter volume loss was observed longitudinally in asymptomatic MAPT and GRN mutation carriers who remained asymptomatic compared to non-carriers (21). The gene discussed is GRN; the disease is Atrophy.