The mutation in charged multivesicular body protein 2B ( CHMP2B ) gene on chromosome 3 was first found in a large Danish pedigree with frontotemporal dementia ( FTD ),which is characterized by frontotemporal lobar degeneration (FTLD) with ubiquitin-immunoreactive inclusions (FTLD-U). Subsequently CHMP2B mutants were found in patients with a non-inherited form of ALS with FTD symptoms designated as ALS-FTD3.