Igarashi H, Momoi M Y, Yamagata T, Shiraishi H, Eguchi I
Department of Pediatrics, Jichi Medical School, Minamikawachi, Tochigi, Japan.
Pediatr Neurol. 1998 Apr;18(4):366-9. doi: 10.1016/s0887-8994(97)00216-6.
Involvement of the cardiac conduction system is a common clinical feature in myotonic dystrophy, whereas the association of primary myocardial abnormalities has rarely been reported. A patient with a severe form of congenital myotonic dystrophy who developed fatal left ventricular hypertrophy at 3 months of age and died at 2 years of age is reported. Serial ultrasonographic studies revealed progressive left ventricular hypertrophy accompanied by outflow obstruction of the left ventricle. Southern analysis for the myotonin kinase gene revealed a 5.8 kb expansion of CTG repeats in addition to a fragment of normal length. The degree of expansion was much greater than those of other reported patients with congenital myotonic dystrophy. These findings suggest that left ventricular hypertrophy represents an extreme level of myocardial damage in myotonic dystrophy and that this damage may be related to the larger size of the CTG repeats.
心脏传导系统受累是强直性肌营养不良的常见临床特征，而原发性心肌异常的关联则鲜有报道。本文报告了一名患有严重先天性强直性肌营养不良的患者，该患者在3个月大时出现致命性左心室肥厚，并于2岁时死亡。系列超声心动图研究显示左心室肥厚进行性加重，并伴有左心室流出道梗阻。对肌强直性蛋白激酶基因的Southern分析显示，除了正常长度的片段外，CTG重复序列扩增至5.8 kb。扩增程度远大于其他报道的先天性强直性肌营养不良患者。这些发现表明，左心室肥厚代表了强直性肌营养不良中心肌损伤的极端程度，且这种损伤可能与CTG重复序列的较大长度有关。
