Liewluck Teerin, Sorenson Eric J, Walkiewicz Magdalena A, Rumilla Kandelaria M, Milone Margherita
Department of Neurology, Mayo Clinic, Rochester, MN, USA.
Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
Neuromuscul Disord. 2017 Aug;27(8):742-746. doi: 10.1016/j.nmd.2017.05.003. Epub 2017 May 5.
Mutations in skeletal muscle α-actin 1-encoding gene (ACTA1) cause autosomal dominant or recessive myopathies with marked clinical and pathological heterogeneity. Patients typically develop generalized or limb-girdle pattern of weakness, but recently a family with scapuloperoneal myopathy was reported. We describe a father and 2 children with childhood-to-juvenile onset distal myopathy, carrying a novel dominant ACTA1 variant, c.757G>C (p.Gly253Arg). Father had delayed motor development and developed significant proximal weakness later in life; he was initially misdiagnosed as having spinal muscular atrophy based on electromyographic findings. His children had predominant anterior distal leg and finger extensor involvement. Nemaline rods were abundant on the daughter's biopsy, absent on the father's initial biopsy, and extremely rare on the father's subsequent biopsy a decade later. The father's second biopsy also showed myofibrillar pathology and rare fibers with actin filament aggregates. The present family expands the spectrum of actinopathy to include a distal myopathy.
骨骼肌α-肌动蛋白1编码基因（ACTA1）突变可导致常染色体显性或隐性肌病，具有显著的临床和病理异质性。患者通常会出现全身性或肢带型肌无力，但最近有一个肩胛腓骨肌病家族被报道。我们描述了一位父亲和两个孩子，他们患有从儿童期到青少年期起病的远端肌病，携带一种新的显性ACTA1变异体，即c.757G>C（p.Gly253Arg）。父亲运动发育迟缓，晚年出现明显的近端肌无力；基于肌电图检查结果，他最初被误诊为脊髓性肌萎缩症。他的孩子主要是小腿前部远端和手指伸肌受累。在女儿的活检中可见大量棒状小体，父亲的初次活检中未发现，十年后父亲的再次活检中则极为罕见。父亲的第二次活检还显示有肌原纤维病理改变以及罕见的带有肌动蛋白丝聚集体的肌纤维。这个家族扩大了肌动蛋白病的范围，使其包括了一种远端肌病。
