Neurology Department, Centro Hospitalar do Porto, Largo do Professor Abel Salazar, 4099-001, Porto, Portugal.
Neuroradiology Department, Centro Hospitalar do Porto, Porto, Portugal.
Neurol Sci. 2018 Apr;39(4):741-744. doi: 10.1007/s10072-018-3268-7. Epub 2018 Feb 13.
The expansion in the C9orf72 gene has been recently reported as a genetic cause of Huntington's disease (HD) phenocopies. We aim to assess the frequency of the C9orf72 gene expansion in a Portuguese HD phenocopies cohort. Twenty HD phenotype-like patients without diagnosis were identified in our institutional database. C9orf72 gene expansion was detected using repeat-primed PCR. Clinical files were reviewed to characterize the phenotype of expansion-positive cases. One patient (5%) was positive for the C9orf72 expansion. A second patient presented 27 repeats-within the intermediate size interval. Both had familial neuropsychiatric disease characterized by diverse movement disorders, dementia, and psychiatric dysfunction that was distinct in severity and clinical expression. C9orf72 disease is clinically heterogeneous and without evident imaging markers. The definition of the role of intermediate alleles and of the pathological threshold for C9orf72 repeat expansions may have diagnostic implications.
C9orf72 基因扩增最近被报道为亨廷顿病（HD）表型副本的遗传原因。我们旨在评估葡萄牙 HD 表型副本队列中 C9orf72 基因扩增的频率。在我们的机构数据库中确定了 20 名具有 HD 表型的无诊断患者。使用重复引物 PCR 检测 C9orf72 基因扩增。回顾临床档案以表征扩增阳性病例的表型。一名患者（5%）的 C9orf72 扩增呈阳性。第二名患者的重复次数在中间大小间隔内为 27 次。两者均具有家族性神经精神疾病，其特征是运动障碍、痴呆和精神功能障碍多种多样，严重程度和临床表现明显不同。C9orf72 疾病的临床表现具有异质性，没有明显的影像学标志物。中间等位基因的作用和 C9orf72 重复扩增的病理阈值的定义可能具有诊断意义。
