BACKGROUND AND OBJECTIVES Facioscapulohumeral dystrophy (FSHD) is an inherited muscle disorder, with childhood onset in 20% of patients. Understanding the natural history of childhood FSHD and identifying clinical and functional outcome measures are crucial for clinical care and future trials. METHODS In a prospective nationwide FSHD cohort study (iFocus), 20 childhood-onset patients were assessed at baseline, 2 years, and 5 years. Assessments included manual muscle and functional muscle tests, FSHD clinical score (FSHD-CS), FSHD clinical severity scale (FSHD-CSS), and muscle ultrasonography (MUS). RESULTS Eighteen patients (aged 2-17 years at baseline) completed the 5-year follow-up. Disease progression varied, with a mean FSHD-CS increase of 1.6. Despite objective disease progression, most participants (89%) did not perceive change. The most sensitive outcome measures were FSHD-CS (standardized response mean [SRM] 1.07), FSHD-CSS score (SRM 0.92), and MUS findings (SRM 0.68). Baseline characteristics did not predict progression. DISCUSSION Disease progression was variable and often remained unnoticed by participants. Quality of life improved, and fatigue levels decreased over 5 years. The relatively slow progression and physiologic growth highlight the need for sensitive end points within a 1-2-year time frame. Future pediatric studies should consider larger international cohorts, assess reachable workspace, and include MUS and FSHD functional composite outcome measure (FSHD-COM).

中文翻译：

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对儿童发病面肩肱营养不良的纵向洞察：一项为期 5 年的自然历史研究。


背景和目的面肩肱骨营养不良 （FSHD） 是一种遗传性肌肉疾病，20% 的患者在儿童期发病。了解儿童 FSHD 的自然病程并确定临床和功能结果指标对于临床护理和未来的试验至关重要。方法 在一项前瞻性全国 FSHD 队列研究 （iFocus） 中，对 20 名儿童期发病患者进行了基线、 2 年和 5 年的评估。评估包括手法肌肉和功能肌肉测试、FSHD 临床评分 （FSHD-CS） 、FSHD 临床严重程度量表 （FSHD-CSS） 和肌肉超声检查 （MUS）。结果 18 例患者 （基线年龄 2-17 岁） 完成了 5 年随访。疾病进展各不相同，平均 FSHD-CS 增加 1.6。尽管客观的疾病进展，但大多数参与者 （89%） 没有感觉到变化。最敏感的结局指标是 FSHD-CS （标准化反应平均值 [SRM] 1.07 ）、FSHD-CSS 评分 （SRM 0.92） 和 MUS 结果 （SRM 0.68）。基线特征不能预测进展。讨论 疾病进展是可变的，参与者经常不会注意到。生活质量提高，疲劳程度在 5 年内下降。相对缓慢的进展和生理性增长凸显了在 1-2 年时间范围内敏感终点的需求。未来的儿科研究应考虑更大的国际队列，评估可到达的工作空间，并包括 MUS 和 FSHD 功能综合结果测量 （FSHD-COM）。