Hereditary spastic paraplegia (HSP) is a group of neurodegenerative diseases with a high genetic and clinical heterogeneity. Numerous HSP patients remain genetically undiagnosed despite screening for known genetic causes of HSP. Therefore, identification of novel variants and genes is needed. Our previous study analyzed 74 adult Serbian HSP patients from 65 families using panel of the 13 most common HSP genes in combination with a copy number variation analysis. Conclusive genetic findings were established in 23 patients from 19 families (29%). In the present study, nine patients from nine families previously negative on the HSP gene panel were selected for the whole exome sequencing (WES). Further, 44 newly diagnosed adult HSP patients from 44 families were sent to WES directly, since many studies showed WES may be used as the first step in HSP diagnosis. WES analysis of cohort 1 revealed a likely genetic cause in five (56%) of nine HSP families, including variants in the ETHE1, ZFYVE26, RNF170, CAPN1, and WASHC5 genes. In cohort 2, possible causative variants were found in seven (16%) of 44 patients (later updated to 27% when other diagnosis were excluded), comprising six different genes: SPAST, SPG11, WASCH5, KIF1A, KIF5A, and ABCD1. These results expand the genetic spectrum of HSP patients in Serbia and the region with implications for molecular genetic diagnosis and future causative therapies. Wide HSP panel can be the first step in diagnosis, alongside with the copy number variation (CNV) analysis, while WES should be performed after.

遗传性痉挛性截瘫（HSP）是一组具有高度遗传和临床异质性的神经退行性疾病。尽管对已知的 HSP 遗传原因进行了筛查，但许多 HSP 患者仍未得到遗传诊断。因此，需要鉴定新的变异和基因。我们之前的研究使用 13 个最常见的 HSP 基因组并结合拷贝数变异分析，分析了来自 65 个家庭的 74 名成年塞尔维亚 HSP 患者。来自 19 个家庭的 23 名患者 (29%) 得到了结论性的基因发现。在本研究中，来自 9 个家庭的 9 名先前 HSP 基因组呈阴性的患者被选择进行全外显子组测序 (WES)。此外，来自44个家庭的44名新诊断的成年HSP患者被直接送往WES，因为许多研究表明WES可以作为HSP诊断的第一步。第 1 组的 WES 分析揭示了 9 个 HSP 家族中的 5 个 (56%) 可能存在遗传原因，包括ETHE1、  ZFYVE26、  RNF170、  CAPN1和WASHC5基因的变异。在队列 2 中，44 名患者中的 7 名 (16%) 发现了可能的致病变异（排除其他诊断后更新为 27%），包括 6 个不同的基因：  SPAST、  SPG11、  WASCH5、  KIF1A、KIF5A和ABCD1。这些结果扩大了塞尔维亚和该地区 HSP 患者的遗传谱，对分子遗传学诊断和未来的病因治疗具有重要意义。广泛的 HSP 检测可以作为诊断的第一步，同时进行拷贝数变异 (CNV) 分析，而 WES 应在之后进行。