Introduction

Hypotonia is a common presentation that child neurologists encounter daily. The hypotonic neonate represents a diagnostic challenge as a lesion at any level in the neuro-axis may cause hypotonia. In this paper, we study the diagnostic yield of investigations commonly used as part of a hypotonia work-up.

Methods

A 12-year retrospective cohort study was conducted at a tertiary care center in Saudi Arabia from 2007 to 2018. Final diagnoses, clinical presentations, laboratory tests, imaging and genetic studies were reviewed from the patient's electronic health records.

Results

164 patients were identified as fitting the inclusion criteria of the study. 50% had central hypotonia, 18% peripheral hypotonia and 32% mixed hypotonia. Molecular testing was performed for 82% (74) of patients. 65 Microarray studies were done; 27% abnormal and 9% diagnostic. 55 gene panels were done; 58% abnormal and 30% diagnostic. 53 single-gene tests were done; 57% abnormal and 40% diagnostic. 61 whole exome sequences were done; 72% positive and 59% diagnostic. 126 MRIs were reviewed; 56% abnormal and 33% contributed to the diagnosis.

Conclusion

Molecular genetic testing is our recommended next step in the diagnosis of patients with hypotonia after careful phenotyping. Neuroimaging is helpful to guide further costly workup of patients with hypotonia.

中文翻译：

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肌张力低下诊断研究的实用性：一项为期 12 年的单中心研究

 介绍

肌张力减退是儿童神经科医生每天都会遇到的常见症状。低渗新生儿代表了诊断挑战，因为神经轴任何水平的病变都可能导致肌张力低下。在本文中，我们研究了肌张力低下检查中常用的检查的诊断率。

 方法

2007年至2018年，沙特阿拉伯一家三级护理中心进行了一项为期12年的回顾性队列研究。根据患者的电子健康记录对最终诊断、临床表现、实验室检查、影像学和基因研究进行了审查。

 结果

164 名患者被确定符合该研究的纳入标准。 50% 患有中枢性肌张力减退，18% 患有外周肌张力减退，32% 患有混合性肌张力减退。对 82% (74) 的患者进行了分子检测。完成了 65 项微阵列研究； 27% 异常，9% 诊断。完成了 55 个基因组； 58% 异常，30% 诊断。进行了53项单基因测试； 57% 异常，40% 诊断。完成了 61 个完整的外显子组序列； 72% 为阳性，59% 为诊断性。审查了 126 幅 MRI； 56% 异常，33% 有助于诊断。

 结论

在仔细进行表型分析后，我们建议进行分子遗传学检测来诊断肌张力低下患者。神经影像学有助于指导肌张力低下患者的进一步昂贵的检查。