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 He became more withdrawn with disinhibited behaviour; his condition progressively worsened and he died 6 years later.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.

中文翻译：

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年轻发病的额颞叶痴呆伴 FUS 病理学


额颞叶痴呆 (FTD) 是导致 50 岁以下成年人行为改变的罕见原因。一名 44 岁男性出现进行性神经精神障碍，其特征为社交退缩、冷漠、失去同理心、运动刻板印象和口欲过多。认知测试发现了严重的损害，包括执行功能障碍。大脑磁共振扫描显示双侧对称额叶萎缩。没有相关家族史，针对 MAPT、GRN 和 C9orf72 基因中 FTD 相关变异的靶向基因检测结果呈阴性。他变得更加孤僻，行为放荡。他的病情逐渐恶化，六年后去世。病理诊断为额颞叶变性伴融合肉瘤（FUS）病理，这是一种罕见的散发性 FTD 病因，仅占病例的 5%~10%，其特征包括发病年龄很小、运动刻板和口欲过多。