Creutzfeldt-Jakob disease (CJD) is a prion disease, usually presented with memory loss, ataxia, dementia, myoclonus, involuntary movements and psychiatric problems. D178N-homozygous 129M genotype has been recognized in the diagnosis of fatal familial insomnia (FFI) globally. Here we report a patient presented with progressive left upper limb stiffness, bradykinesia, hypomimia and weight loss (10 kg) initially. She progressed to dementia, dysphasia, dysphonia and be bedridden quickly but did not present insomnia. She was diagnosed with CJD corticobasal subtype carrying a classic D178N-129M mutation of PRNP in FFI. Remarkably, she has a strong family history of neurological degeneration diseases but the other members of this pedigree who do not carry D178N-homozygous 129M mutation in PRNP do not present any CJD or FFI symptoms. We conclude that this patient carrying D178N-homozygous 129M mutation in PRNP should be diagnosed as CJD. Thus, the clinicopathology should be considered as a crucial evidence in diagnosing some cases, but FFI could be evaluated as a differential diagnosis with a unique clinical profile.

List of abbreviations

AD: Alzheimer disease; ADL: Activities of Daily Living; CBD Cortical basal degeneration; CBS: Corticobasal syndrome; CJD: Creutzfeldt-Jakob disease; DWI: Diffusion-weighted image; EEG: Electroencephalograph, fCJD: familial Creutzfeld-Jakob disease; FFI: Fatal familial insomnia; FLAIR: Fluid-attenuated inversion recovery; MMSE: Mini-mental state examination; MoCA: Montreal Cognitive Assessment; MRI: Magnetic resonance imaging; PD: Parkinson disease; PrP: Prion protein; PSWC: Periodic sharp wave complexes; SWI: Susceptibility-weighted imaging

克雅氏病 (CJD) 是一种朊病毒病，通常表现为记忆力减退、共济失调、痴呆、肌阵挛、不自主运动和精神问题。D178N 纯合 129M 基因型已在全球范围内用于致命性家族性失眠 (FFI) 的诊断。在这里，我们报告了一名患者最初表现为进行性左上肢僵硬、运动迟缓、拟态减退和体重减轻（10 公斤）。她迅速发展为痴呆、言语障碍、发音困难和卧床不起，但没有失眠。她被诊断为 CJD 皮质基底细胞亚型，携带FFI中PRNP的典型 D178N-129M 突变。值得注意的是，她有很强的神经退行性疾病家族史，但该系谱的其他成员没有携带 D178N 纯合 129M 突变的PRNP不要出现任何 CJD 或 FFI 症状。我们得出结论，该患者在PRNP 中携带 D178N 纯合 129M 突变应诊断为 CJD。因此，临床病理学应被视为诊断某些病例的关键证据，但 FFI 可作为具有独特临床特征的鉴别诊断进行评估。

缩略语表

AD：阿尔茨海默病；ADL：日常生活活动；CBD 皮质基底变性；CBS：皮质基底节综合征；CJD：克雅氏病；DWI：扩散加权图像；EEG：脑电图，fCJD：家族性克雅氏病；FFI：致死性家族性失眠症；FLAIR：流体衰减反转恢复；MMSE：简易精神状态检查；MoCA：蒙特利尔认知评估；MRI：磁共振成像；PD：帕金森病；PrP：朊病毒蛋白；PSWC：周期尖波复合波；SWI：磁敏感加权成像