Secondary mania as a possible presentation of a C9orf72 hexanucleotide repeat expansion.

C9Orf72 hexanucelotide repeat expansions have been associated with ALS and FTD. Although various psychiatric symptoms have been described in patients with C9Orf72 hexanucleotide repeat expansions, the full clinical spectrum has not yet been elucidated. There is increasing evidence that inflammation plays a role in the disease progression of ALS and FTD (1) and immune dysfunction is strongly associated with bipolar disorder. We present a case in which we hypothesize that inflammation may trigger a secondary mania as an expression of latent FTD/ALS in an older male C9orf72 hexanucleotide repeat expansion carrier. We also review the literature on psychiatric disease in association with FTD and C9orf72 hexanucleotide repeat expansions. This article is protected by copyright. All rights reserved.