Don Carlo Gnocchi Onlus Foundation, Milan, Italy.
J Neurol. 2012 Jul;259(7):1358-65. doi: 10.1007/s00415-011-6357-6. Epub 2012 Jan 10.
GNE myopathy (MIM 600737) is an autosomal recessive muscle disease caused by mutations in the UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase (GNE) gene. Besides the typical phenotype, characterized by the initial involvement of the distal leg muscles that eventually spreads proximally with sparing of the quadriceps, uncommon presentations with a non-canonical clinical phenotype, unusual muscle biopsy findings or both are increasingly recognized. The aim of our study was to characterize the imaging pattern of pelvic and lower limb muscles in GNE myopathy, thus providing additional diagnostic clues useful in the identification of patients with atypical features. We retrospectively evaluated muscle MRI and CT scans of a cohort of 13 patients heterogeneous for GNE mutations and degree of clinical severity. We found that severe involvement of the biceps femoris short head and, to a lesser extent, of the gluteus minimus, tibialis anterior, extensor hallucis and digitorum longus, soleus and gastrocnemius medialis was consistently present even in patients with early or atypical disease. The vastus lateralis, not the entire quadriceps, was the only muscle spared in advanced stages, while the rectus femoris, vastus intermedius and medialis showed variable signs of fatty replacement. Younger patients showed hyperintensities on T2-weighted sequences in muscles with a normal or, more often, abnormal T1-weighted signal. Our results define a pattern of muscle involvement that appears peculiar to GNE myopathy. Although these findings need to be further validated in a larger cohort, we believe that the recognition of this pattern may be instrumental in the initial clinical assessment of patients with possible GNE myopathy.
GNE 肌病(MIM 600737)是一种由 UDP-N-乙酰氨基葡萄糖 2-差向异构酶/N-乙酰甘露糖胺激酶(GNE)基因突变引起的常染色体隐性肌肉疾病。除了以远端腿部肌肉最初受累为特征的典型表型外,随着近端肌肉逐渐受累,股四头肌不受累,不常见的表现为非典型临床表型、不典型肌肉活检发现或两者兼有,越来越受到关注。我们的研究目的是描述 GNE 肌病骨盆和下肢肌肉的影像学表现,从而提供更多有助于识别具有非典型特征的患者的额外诊断线索。我们回顾性评估了 13 名患者的肌肉 MRI 和 CT 扫描,这些患者的 GNE 基因突变和临床严重程度存在异质性。我们发现,即使在疾病早期或不典型的患者中,也始终存在严重累及比目鱼肌短头和较小程度的臀小肌、胫骨前肌、伸趾长肌、腓骨长肌和比目鱼肌和腓肠肌内侧。在晚期,仅股外侧肌不受累,而整个股四头肌都受累;股直肌、股中间肌和股内侧肌则显示出不同程度的脂肪替代。年轻患者的肌肉在 T2 加权序列上显示高信号,而 T1 加权信号正常或更常见异常。我们的结果定义了一种肌肉受累模式,这种模式似乎是 GNE 肌病所特有的。尽管这些发现需要在更大的队列中进一步验证,但我们认为识别这种模式可能有助于对可能患有 GNE 肌病的患者进行初始临床评估。