A nonsense/protein chain-terminating mutation in the CHMP2B gene has recently been reported as a cause of frontotemporal dementia (FTD) in the single large family known to show linkage to chromosome 3. Screening for mutations in this gene in a large series of FTD families and individual patients led to the identification of a protein-truncating mutation in 2 unaffected members of an Afrikaner family with FTD, but not in their affected relatives. The putative pathogenicity of CHMP2B mutations for dementia is discussed.