Abnormal increases in ventricular volumes occur in the prodromal phase of genetic frontotemporal dementia (FTD), a recent study has indicated. The study included individuals from families with genetic FTD who were enrolled in the Genetic Frontotemporal Dementia Initiative. The participants included 46 presymptomatic people with mutations in MAPT, PGRN or C9orf72, and 56 people from the same families who carried no FTD-associated mutations. Analysis of MRI data obtained at baseline and 1 year later showed that total ventricular volumes were larger in mutation carriers than in non-carriers up to 4 years before estimated symptom onset. The investigators say that their findings support the use of ventricular volume as an index of symptom onset in people with FTD-associated mutations, but long-term follow-up is needed to confirm this conclusion.