TY - JOUR T1 - Young-onset frontotemporal dementia with FUS pathology JF - Practical Neurology JO - Pract Neurol SP - 149 LP - 152 DO - 10.1136/practneurol-2020-002730 VL - 21 IS - 2 AU - Matthew Gowell AU - Ian Baker AU - Olaf Ansorge AU - Masud Husain Y1 - 2021/04/01 UR - http://pn.bmj.com/content/21/2/149.abstract N2 - Frontotemporal dementia (FTD) is an uncommon cause of behavioural change in adults under the age of 50. A 44-year-old man presented with progressive neuropsychiatric disturbance characterised by social withdrawal, apathy, loss of empathy, motor stereotypies and hyperorality. Cognitive testing identified severe impairment, including executive dysfunction. MR scan of the brain showed bilateral symmetrical frontal atrophy. There was no relevant family history, and targeted genetic testing for FTD-associated variants in MAPT, GRN and C9orf72 genes proved negative. He became more withdrawn with disinhibited behaviour; his condition progressively worsened and he died 6 years later. The pathological diagnosis was frontotemporal lobar degeneration with fused-in-sarcoma (FUS) pathology, a rare sporadic cause of FTD, accounting for only 5%–10% of cases, its characteristic features including very young onset, motor stereotypies and hyperorality. ER -