Background: It is unclear whether there are early clinical features that can distinguish between patients with familial and non-familial frontotemporal dementia (FTD).
Objective: To compare the clinical features of FTD cases who have tau gene mutations with those of cases with a family history of FTD but no tau gene mutation, and with sporadic cases with neither feature.
Methods and results: Comparisons of the behavioural, cognitive, and motor features in 32 FTD patients (five positive for tau gene mutations, nine familial but tau negative, and 18 tau negative sporadic) showed that age of onset and duration to diagnosis did not differ between the groups. Apathy was not observed in tau mutation positive cases, and dysexecutive signs were more frequent in familial tau mutation negative cases. Memory deficits and behavioural changes were common in all groups.
Conclusions: In comparison with other neurodegenerative conditions such as Alzheimer's disease and Parkinson's disease, neither tau gene mutations nor strong familial associations confer earlier disease susceptibility.