This finding is all the more striking, given that ALS, in general, is reported to be more common in men with a ratio of males to females of 1.7:1 [21] and could indicate that some factor associated with biological sex affects the penetrance of TIA1 mutations, similar to what has been reported for some other genetic subtypes of ALS/FTD [6]. Here, TIA1 is linked to frontotemporal dementia.