Recently the scientific community has started to view Bethlem myopathy 1 and Ullrich congenital muscular dystrophy as two extremes of a collagen VI-related myopathy spectrum rather than two separate entities, as both are caused by mutations in one of the collagen VI genes. Here we report three individuals in two families who are homozygous for a COL6A3 mutation (c.7447A> G; p.Lys2483Glu), and compare their clinical features with seven previously published cases. Individuals carrying homozygous or compound heterozygous c.7447A> G, (p.Lys2483Glu) mutation exhibit mild phenotype without loss of ambulation, similar to the cases described previously as Collagen VI-related limb-girdle syndrome. The phenotype could arise due to an aberrant assembly of Von Willebrand factor A domains. Based on these data, we propose that c.7447A> G, (p.Lys2483Glu) is a common pathogenic mutation.

中文翻译：

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由 COL6A3 基因频繁突变引起的胶原蛋白 VI 相关的肢带综合征与致病性报告相互矛盾

最近，科学界开始将 Bethlem 肌病 1 和 Ullrich 先天性肌营养不良症视为 VI 型胶原相关肌病谱的两个极端，而不是两个独立的实体，因为两者都是由 VI 型胶原基因之一的突变引起的。在这里，我们报告了两个家族中的三个个体，他们是 COL6A3 突变纯合子（c.7447A> G；p.Lys2483Glu），并将他们的临床特征与之前发表的七个病例进行比较。携带纯合子或复合杂合子 c.7447A> G, (p.Lys2483Glu) 突变的个体表现出轻微的表型，而不会失去行走能力，类似于之前描述的胶原蛋白 VI 相关的肢带综合征。该表型可能是由于 Von Willebrand 因子 A 结构域的异常组装而出现的。基于这些数据，我们建议 c.7447A> G, (p.