Tenascin-X, is an extracellular matrix glycoprotein expressed in skin, muscle, tendons, and blood vessels with an anti-adhesive function. Biallelic Tenascin-X mutations cause classical-like Ehlers-Danlos syndrome. We report a 46-year-old woman with slowly progressive weakness of the lower limbs and myalgia from age 28 years. In the past she had Raynaud's phenomenon, multiple sprains and joint dislocations, conjunctival haemorrhages and a colonic perforation during colonoscopy. Neurologic examination showed moderate asymmetric proximal and axial muscular weakness, distal amyotrophy of 4 limbs, moderate skin hyperextensibility, and hypermobility of distal joints of fingers. Whole body Magnetic Resonance Imaging showed symmetric fatty infiltration of thigh and leg muscles, with predominant atrophy of thighs. Next Generation Sequencing revealed two pathogenic TNXB variants, g.32024681C>G, c.7826-1G>C, and g.32016181dup, c.9998dupA, p.(Asn3333Lysfs*35). Western Blot and immunofluorescence studies confirmed a marked Tenascin-X reduction in both patient's serum and muscle. Here we further detail the clinical and genetic spectrum of a patient with classical-like Ehlers-Danlos syndrome and prominent muscle involvement.

中文翻译：

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Tenascin-X 中的双等位基因突变导致经典样 Ehlers-Danlos 综合征伴缓慢进行性肌肉无力

Tenascin-X 是一种在皮肤、肌肉、肌腱和血管中表达的细胞外基质糖蛋白，具有抗粘连功能。双等位生腱蛋白-X 突变导致经典样 Ehlers-Danlos 综合征。我们报告了一名 46 岁女性，她从 28 岁开始下肢缓慢进行性无力和肌痛。过去，她曾在结肠镜检查中出现过雷诺现象、多处扭伤和关节脱位、结膜出血和结肠穿孔。神经系统检查显示中度不对称近端和轴向肌肉无力，4 肢远端肌萎缩，中度皮肤过度伸展和手指远端关节过度活动。全身磁共振成像显示大腿和腿部肌肉对称的脂肪浸润，以大腿萎缩为主。下一代测序揭示了两种致病性 TNXB 变异，g.32024681C>G，c.7826-1G>C 和 g.32016181dup，c.9998dupA，p.(Asn3333Lysfs*35)。蛋白质印迹和免疫荧光研究证实，患者血清和肌肉中的 Tenascin-X 显着减少。在这里，我们进一步详细介绍了典型的 Ehlers-Danlos 综合征和突出的肌肉受累患者的临床和遗传谱。