Since the clinical picture seemed to mimic different forms of neurodegenerative diseases in an atypical way, we decided to carry out on this family a large linkage analysis on 26 genes which were known to cause hereditary dementias (i.e., APP, PSEN1, PSEN2, FTDP-17, BRI, PI12, FND, HD-like, SCA1, SCA2, SCA3, SCA4, SCA5, SCA6, SCA7, SCA8, SCA10, SCA11, SCA12, SCA13, PARK1, PARK2, PARK3, HD, DRPLA, PRNP). Here, HTT is linked to hereditary dementia.