Abstract: Objective　To explore the clinical features of hereditary spastic paraplegia（HSP） SPG 31 and the pathogenic mechanism of REEP1 gene mutation. Methods　The clinical data of a HSP family（SPG 31） and their gene sequencing results were retrospectively analyzed and literatures were reviewed. Results　In the family，6 members over 3 generations carried a novel heterozygous mutation in the REEP1 gene - c.425del（p.Gly142Valfs*81） with strong pathogenicity，which was not reported before，whose clinical symptoms varied in severity，mainly manifested by weakness of lower limbs，walking instability and spasm gait，and the proband presented with a slow progressive aggravation. Conclusion　HSP has significant clinical and genetic heterogeneity，and a novel REEP1 gene mutation may be the cause of  HSP in this family，but the exact conclusion needs to be further verified.

Key words: Hereditary spastic paraplegia, SPG31 type, REEP1 gene

摘要： 目的　探讨遗传性痉挛性截瘫（HSP）SPG31型的临床特征及REEP1基因突变的致病机制。方法　回顾性分析2018年9月华中科技大学同济医学院附属同济医院儿科收治的一家系HSP SPG31型的临床资料和基因检测结果并进行文献复习。结果　该HSP家系3代共6例成员携带REEP1基因杂合突变c.425del（p.Gly142Valfs*81），该变异属未报道的新发强致病变异，患者临床表现轻重不等，主要表现双下肢无力、走路不稳及痉挛步态，先证者呈缓慢进行性加重。结论　HSP具有显著临床和遗传异质性，REEP1基因新的位点突变可能是引起该家系发病的原因，但确切结论尚需进一步验证。

关键词: 遗传性痉挛性截瘫, SPG31型, REEP1基因