Academic Department of Neurosciences, Royal Hallamshire Hospital, Sheffield Teaching Hospitals NHS Trust and University of Sheffield, Sheffield, UK
Department of Neuromuscular Disease, UCL Queen Square Institute of Neurology, London, UK.
J Neurol Neurosurg Psychiatry. 2024 Jan 11;95(2):171-174. doi: 10.1136/jnnp-2023-331381.
Biallelic expansion of AAGGG in the replication factor complex subunit 1 () was identified as a major cause of cerebellar ataxia, neuropathy (sensory ganglionopathy, or SG) and vestibular areflexia syndrome (CANVAS). We wanted to clarify if expansions can present with pure ataxia and if such expansions could be responsible for some cases where an alternative diagnosis had been made.
We identified patients with a combination of ataxia and SG and no other cause found, patients where an alternative diagnosis had been made, and patients with pure ataxia. Testing for expansions was done using established methodology.
Among 54 patients with otherwise idiopathic sporadic ataxia without SG, none was found to have expansions. Among 38 patients with cerebellar ataxia and SG in which all other causes were excluded, 71% had expansions. Among 27 patients with cerebellar ataxia and SG diagnosed with coeliac disease or gluten sensitivity, 15% had expansions.
Isolated cerebellar ataxia without SG makes the diagnosis of CANVAS due to expansions highly improbable, but CANVAS is frequently the cause of the combination of idiopathic cerebellar ataxia with SG. It is important to screen patients diagnosed with other causes of acquired ataxia and SG as a small percentage were found to have expansions.
复制因子复合物亚基 1 () 中的 AAGGG 双等位基因扩展被确定为小脑共济失调、神经病（感觉神经节病，或 SG）和前庭反射消失综合征（CANVAS）的主要原因。我们想阐明是否存在仅表现为纯共济失调的 扩展，以及此类扩展是否可能导致一些被诊断为其他疾病的病例。
我们确定了同时存在共济失调和 SG 且未发现其他病因的患者、已做出其他诊断的患者以及仅存在共济失调的患者。使用既定方法检测 是否存在扩展。
在 54 名无 SG 的特发性散发性共济失调患者中，均未发现 扩展。在 38 名排除所有其他病因的小脑共济失调和 SG 患者中，71%存在 扩展。在 27 名被诊断为乳糜泻或麸质敏感性的小脑共济失调和 SG 患者中，15%存在 扩展。
孤立性无 SG 的小脑共济失调使得由于 扩展引起的 CANVAS 诊断极不可能，但 CANVAS 经常是特发性小脑共济失调与 SG 合并的原因。筛选被诊断为其他获得性共济失调和 SG 病因的患者非常重要，因为一小部分患者被发现存在 扩展。
