Doo Ki Hyun, Ryu Hye Won, Kim Seung Soo, Lim Byung Chan, Hwang Hui, Kim Ki Joong, Hwang Yong Seung, Chae Jong-Hee
Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea.
Korean J Pediatr. 2012 Sep;55(9):350-3. doi: 10.3345/kjp.2012.55.9.350. Epub 2012 Sep 14.
An 18-year-old boy was admitted with chest discomfort, nausea, and dyspnea at rest. At the age of 3 years, he underwent muscle biopsy and dystrophin gene analysis owing to an enlarged calf muscle and elevated serum kinase level (6,378 U/L) without overt weakness; based on the results, Becker muscular dystrophy (BMD) was diagnosed. The dystrophin gene showed deletion of exons 45 to 49. He remained ambulant and could step upstairs without significant difficulties. A chest roentgenogram showed cardiomegaly (cardiothoracic ratio, 54%), and his electrocardiogram (ECG) showed abnormal ST-T wave, biatrial enlargement, and left ventricular hypertrophy. The 2-dimensional and M-mode ECGs showed a severely dilated left ventricular cavity with diffuse hypokinesis. The systolic indices were reduced, including fractional shortening (9%) and ejection fraction (19%). Despite receiving intensive medical treatment, he died from congestive heart failure 5 months after the initial cardiac symptoms. We report a case of BMD with early-onset dilated cardiomyopathy associated with deletion of exons 45 to 49. Early cardiomyopathy can occur in BMD patients with certain genotypes; therefore, careful follow-up is required even in patients with mild phenotypes of BMD.
一名18岁男孩因胸部不适、恶心及静息时呼吸困难入院。3岁时，因小腿肌肉增大及血清激酶水平升高（6378 U/L）但无明显肌无力，他接受了肌肉活检及肌营养不良蛋白基因分析；根据结果，诊断为贝克型肌营养不良（BMD）。肌营养不良蛋白基因显示外显子45至49缺失。他仍能行走，上楼也无明显困难。胸部X线片显示心脏扩大（心胸比率54%），其心电图（ECG）显示ST-T波异常、双房扩大及左心室肥厚。二维及M型心电图显示左心室腔严重扩张伴弥漫性运动减弱。收缩期指标降低，包括缩短分数（9%）及射血分数（19%）。尽管接受了强化治疗，他在出现最初心脏症状5个月后死于充血性心力衰竭。我们报告一例BMD合并早发性扩张型心肌病且外显子45至49缺失的病例。特定基因型的BMD患者可发生早期心肌病；因此，即使是BMD轻度表型的患者也需要密切随访。
