Background Human prion diseases are a group of rare neurological diseases with a minority due to genetic mutations in the prion protein (PRNP) gene. The D178N mutation is associated with both Creutzfeldt-Jakob disease and fatal familial insomnia with the phenotype modified by a polymorphism at codon 129 with the methionine/valine (MV) polymorphism associated with atypical presentations leading to diagnostic difficulty. Case We present a case of fatal familial insomnia secondary to a PRNP D178N mutation with 129MV disease modifying polymorphism who had no family history, normal MRI, electroencephalography (EEG), cerebrospinal fluid (CSF) and positron emission tomography findings and a negative real-time quaking-induced conversion result. Conclusion Patients with genetic prion disease may have no known family history and normal EEG, MRI brain and CSF findings. PRNP gene testing should be considered for patients with subacute progressive neurological and autonomic dysfunction.

中文翻译：

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遗传性朊病毒病：具有 129MV 疾病修饰多态性的 D178N——一种临床表型

背景 人类朊病毒疾病是一组罕见的神经系统疾病，其中少数是由于朊病毒蛋白（PRNP）基因的基因突变所致。D178N 突变与 Creutzfeldt-Jakob 病和致命的家族性失眠症相关，其表型由密码子 129 的多态性修饰，蛋氨酸/缬氨酸 (MV) 多态性与非典型表现相关，导致诊断困难。案例我们介绍了一个致命的家族性失眠病例，该病例继发于 PRNP D178N 突变，具有 129MV 疾病修饰多态性，没有家族史，没有正常的 MRI、脑电图 (EEG)、脑脊液 (CSF) 和正电子发射断层扫描结果以及阴性实时地震引起的转换结果。结论 遗传性朊病毒病患者可能无已知家族史，脑电图正常，MRI 脑和脑脊液检查结果。亚急性进行性神经和自主神经功能障碍的患者应考虑进行 PRNP 基因检测。