Department of Neurology, Centro Hospitalar Universitário de São João, E.P.E., Porto, Portugal.
Department of Clinical Neurosciences and Mental Health, Faculty of Medicine, University of Porto, Porto, Portugal.
J Neuromuscul Dis. 2022;9(5):649-654. doi: 10.3233/JND-220823.
Emery-Dreifuss Muscular Dystrophy (EDMD) is an early-onset, slowly-progressive group of myopathies, presenting with joint contractures, muscle weakness and cardiac abnormalities. Variants in the EMD gene cause an X-linked recessive form (EDMD1). The scarce EDMD1 muscle MRI accounts in the literature describe fatty replacement of posterior thigh and leg muscles.We report a 22-year-old patient with early-onset bilateral joint contractures, slowly progressive muscle weakness and minor cardiac rhythm abnormalities. A novel loss-of-function variant of EMD was identified and deemed probably pathogenic in the absence of emerin detection by immunofluorescence and Western Blot. MRI revealed fatty replacement of the lumbar spinal erectors and the posterior compartment of lower limbs. Interestingly, Short Tau Inversion Recovery (STIR) sequences showed a heterogenous hyper signal on the vasti, hamstrings and left lateral gastrocnemius muscles.Oedema-like abnormalities were previously reported in early stages of other muscular dystrophies, preceding fatty replacement and muscle atrophy, but not in EDMD1 patients. We hypothesize that these oedema-like changes may be a marker of early muscle pathology in EDMD1. Further studies focusing on these abnormalities in the early phase of EDMD1 are required to test our hypothesis.
先天性肌营养不良症（EDMD）是一种早发、进行性缓慢的肌病，表现为关节挛缩、肌肉无力和心脏异常。EMD 基因突变导致 X 连锁隐性遗传形式（EDMD1）。文献中罕见的 EDMD1 肌肉 MRI 描述了后大腿和小腿肌肉的脂肪替代。我们报告了一名 22 岁患者，其表现为早发性双侧关节挛缩、进行性缓慢的肌肉无力和轻微的心律失常。发现了一种新型的 EMD 功能丧失变异，在免疫荧光和 Western Blot 检测不到 emerin 的情况下，被认为可能是致病性的。MRI 显示腰椎竖脊肌和下肢后区的脂肪替代。有趣的是，短回波反转恢复（STIR）序列显示股四头肌、腘绳肌和左侧外侧比目鱼肌呈不均匀高信号。水肿样异常以前曾在其他肌肉营养不良的早期阶段报道过，先于脂肪替代和肌肉萎缩，但在 EDMD1 患者中没有。我们假设这些水肿样变化可能是 EDMD1 早期肌肉病理学的标志。需要进一步研究这些在 EDMD1 早期阶段的异常，以验证我们的假设。
