CHMP2B is a gene located in the short arm of chromosome 3, contains six exons and encodes a protein that is a component of the endosomal sorting complex required for transport-III (ESCRT-III), essential for maturation of early endosomes towards multivesicular bodies.3 The first time that a dominant mutation in CHMP2B was identified as a cause for FTD was in a Danish family,4 where a change in the acceptor splicing site of intron 5 led to aberrant splicing of the mRNA, causing enlarged endosomes5 and affecting the fusion of endosomes with lysosomes.6 The gene discussed is CHMP2B; the disease is frontotemporal dementia.