Neuropsychological features of asymptomatic c.709-1G>A progranulin mutation carriers

Mutations in the progranulin (PGRN) gene have been identified as a cause of frontotemporal dementia (FTD). However, little is known about the neuropsychological abilities of asymptomatic carriers of these mutations. The aim of the study was to assess cognitive functioning in asymptomatic c.709-1G>A PGRN mutation carriers. We hypothesized that poorer neuropsychological performance could be present before the development of clinically significant FTD symptoms. Thirty-two asymptomatic first-degree relatives of FTD patients carrying the c.709-1G>A mutation served as study participants, including 13 PGRN mutation carriers (A-PGRN+) and 19 non-carriers (PGRN-). A neuropsychological battery was administered. We found that the A-PGRN+ participants obtained significantly poorer scores than PGRN- individuals on tests of attention (Trail-Making Test Part A), mental flexibility (Trail-Making Test Part B), and language (Boston Naming Test). Poorer performance on these tests in asymptomatic PGRN mutation carriers may reflect a prodromal phase preceding the onset of clinically significant symptoms of FTD.