Objective

To describe clinical and genetic studies on a patient with early-onset spinal muscular atrophyX3 (SMAX3) with novel variant of ATP7A.

Methods

Clinical, neurophysiological, neuroimaging and pathological examinations were performed. Whole exome sequencing was applied to search genetic bases of this patient.

Results

The patient had gait abnormality from early infantile period. Muscle imaging at 42 years old showed predominant involvement of proximal muscles as compared to the distal muscles. The patient had a novel variant of ATP7A, which was the fourth genotype of ATP7A exhibited as SMAX3. Contrary to previous reports of distal motor neuropathy, the clinical and neuroimaging findings in this case revealed dominant involvement in the proximal portion of the extremities and trunk, which is similar to patients with type III SMA.

Conclusion

The dominant involvement of proximal motor system in this patient may expand the phenotypic variability of SMAX3. We need to be aware of this disorder in differential diagnosis of patients with type III SMA-like phenotype.

中文翻译：

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一名患有早发性 SMAX3 和 ATP7A 新变体的患者

客观的

描述对具有ATP7A新变体的早发性脊髓性肌萎缩症 X3 (SMAX3) 患者的临床和遗传学研究。

方法

进行了临床、神经生理学、神经影像学和病理学检查。应用全外显子组测序来搜索该患者的遗传碱基。

结果

患者从婴儿期开始就有步态异常。与远端肌肉相比，42 岁的肌肉成像显示近端肌肉主要受累。该患者有一个新的ATP7A变体，这是 ATP7A 的第四个基因型，表现为 SMAX3。与先前关于远端运动神经病变的报道相反，该病例的临床和神经影像学检查结果显示四肢和躯干的近端部分主要受累，这与 III 型 SMA 患者相似。

结论

该患者近端运动系统的主要受累可能会扩大 SMAX3 的表型变异性。我们需要在 III 型 SMA 样表型患者的鉴别诊断中意识到这种疾病。