Ataxia pancytopenia (ATXPC) syndrome due to gain‐of‐function pathogenic variants in the SAMD9L gene has been described in 38 patients to date. It is characterized by variable neurological and hematological phenotypes including ataxia, pyramidal signs, cytopenias, and hematological malignancies. Peripheral neuropathy with slowing of conduction velocities has been reported in only two affected individuals. We describe a female with childhood onset neuropathy diagnosed as Charcot‐Marie‐Tooth disease type 1 with onset of cerebellar ataxia in her 50s. Cerebellar, pyramidal, and neuropathic features were found on examination. Additionally, she also had conjunctival telangiectasia. Nerve conduction studies confirmed a demyelinating neuropathy. MRI brain showed cerebellar atrophy with diffuse white matter hyperintensities. OCT demonstrated global thinning of the retinal nerve fiber layer (RNFL). Full blood count has always been normal. A previously described pathogenic variant in SAMD9L [c.2956C>T p.(Arg986Cys)] was identified on whole exome sequencing. This case extends the previously described phenotype to include conjunctival telangiectasia and RNFL thinning and suggests that ATXPC syndrome should be considered in the differential for inherited demyelinating neuropathies.

中文翻译：

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SAMD9L 突变导致的共济失调全血细胞减少综合征表现为脱髓鞘性神经病。

共济失调全血细胞减少（ATXPC）综合征由于增益的功能致病在变SAMD9L迄今为止，已在 38 名患者中描述了该基因。它的特点是可变的神经和血液表型，包括共济失调、锥体征、血细胞减少和血液系统恶性肿瘤。仅在两名受影响的个体中报告了伴有传导速度减慢的周围神经病变。我们描述了一名患有儿童期神经病的女性，被诊断为 Charcot-Marie-Tooth 病 1 型，并在 50 多岁时出现小脑共济失调。检查发现小脑、锥体和神经性特征。此外，她还患有结膜毛细血管扩张症。神经传导研究证实了脱髓鞘性神经病。MRI 大脑显示小脑萎缩伴弥漫性白质高信号。OCT 显示视网膜神经纤维层 (RNFL) 整体变薄。全血细胞计数一直正常。SAMD9L [c.2956C>T p.(Arg986Cys)] 在全外显子组测序中得到鉴定。该病例扩展了先前描述的表型，包括结膜毛细血管扩张和 RNFL 变薄，并表明在鉴别遗传性脱髓鞘性神经病时应考虑 ATXPC 综合征。