Laing early onset distal myopathy: slow myosin defect with variable abnormalities on muscle biopsy
Laing early onset distal myopathy: slow myosin defect with variable abnormalities on muscle biopsy
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DOI：
10.1136/jnnp.2005.073825
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发表时间：
2006-02-01
影响因子：
11
通讯作者：
Laing, NG
中科院分区：
文献类型：
--
作者：
Lamont, PJ;Udd, B;Laing, NG
背景资料：早发型远端肌病（MPD 1）是由慢骨骼肌纤维肌球蛋白重链基因MYH 7突变引起的常染色体显性遗传性肌病。它与肌球蛋白沉积性肌病、最常见的家族性肥厚型心肌病和一种扩张型心肌病等位。然而，MPD 1的临床图片是从这三个condition.Objective不同：整理和讨论的组织学特征报告的肌肉活检MPD 1患者和概述的临床feature.Results：MPD 1的表型是一致的，与最初的弱点，大脚趾/踝关节背屈，和后来的发展无力的手指伸展和颈部屈曲。发病年龄是唯一的变量，从出生到20多岁，但进展总是非常缓慢。病理特征多样。在这个回顾性系列中，没有特异性的诊断特征，尽管在一半的家族中发现了萎缩的I型纤维。除了Myoshi远端肌病外，在所有其他远端肌病中均观察到边缘空泡。然而，它们在少数MPD 1患者中发现，并且在存在时并不突出。慢肌球蛋白和快肌球蛋白的免疫组化染色显示，在一些I型纤维的慢肌球蛋白和快肌球蛋白的共同表达，可能表明开关到II型状态。这可能是一个有用的辅助diagnosis.Conclusions：在MPD 1的病理结果是可变的，似乎是受影响的因素，如特定的肌肉活检，活检时患者的年龄，和疾病表现的持续时间。
Background: Laing early onset distal myopathy (MPD1) is an autosomal dominant myopathy caused by mutations within the slow skeletal muscle fibre myosin heavy chain gene, MYH7 It is allelic with myosin storage myopathy, with the commonest form of familial hypertrophic cardiomyopathy, and with one form of dilated cardiomyopathy. However, the clinical picture of MPD1 is distinct from these three conditions.Objective: To collate and discuss the histological features reported in the muscle biopsies of MPD1 patients and to outline the clinical features.Results: The phenotype of MPD1 was consistent, with initial weakness of great toe/ankle dorsiflexion, and later development of weakness of finger extension and neck flexion. Age of onset was the only variable, being from birth up to the 20s, but progression was always very slow. The pathological features were variable. In this retrospective series, there were no pathognomonic diagnostic features, although atrophic type I fibres were found in half the families. Rimmed vacuoles are consistently seen in all other distal myopathies with the exception of Myoshi distal myopathy. However, they were found in a minority of patients with MPD1, and were not prominent when present. Immunohistochemical staining for slow and fast myosin showed co-expression of slow and fast myosin in some type I fibres, possibly indicating a switch to type II status. This may be a useful aid to diagnosis.Conclusions: The pathological findings in MPD1 are variable and appear to be affected by factors such as the specific muscle biopsied, the age of the patient at biopsy, and the duration of disease manifestations.