婴幼儿贝克型肌营养不良17例临床 遗传及骨骼肌病理特征分析

Clinical,pathologic and genetic features of 17 infants with Becker muscular dystrophy.

目的探讨婴幼儿贝克型肌营养不良(BMD)临床、DMD基因突变及骨骼肌病理特征。方法 2009年6月至2013年3月深圳市儿童医院神经肌肉病研究室专科门诊通过DMD基因检测和肌肉活检确诊为BMD男性婴幼儿17例,年龄3～36个月,平均年龄(24±12)个月。对患儿临床表现、血清肌酸激酶(CK)、天门冬氨酸氨基转移酶(AST)、丙氨酸氨基转移酶(ALT)、基因检查以及骨骼肌病理变化进行回顾性分析。结果 (1)婴幼儿BMD无或仅有轻微肌营养不良临床表现;(2)CK、AST、ALT分别为正常值上限的35、3、2.7倍,CK与AST(r=0.892,P<0.01)、CK与ALT(r=0.819,P<0.01)之间有正相关;(3)DMD基因检查非移码缺失突变15例(88%);(4)肌肉活检:肌纤维大小不等,坏死和再生肌纤维呈灶状分布,脂肪结缔组织轻度增生。肌纤维膜上抗Dystrophy-C、N、R抗体免疫染色不均匀或阳性纤维之间阴性纤维呈斑片状分布。结论血清CK和转氨酶升高是诊断BMD的重要生化指标,DMD基因检测和骨骼肌dystrophin免疫组织化学检查是确诊BMD的重要手段。

Objective To study the clinical, pathological and genetic features in infants with Becker muscular dystrophy （BMD）, with the aim of increasing the possibility of early diagnosis. Methods The clinical data of 17 infants＇ who were definitely diagnosed with BMD, based on clinical manifestations, serum creatine kinase, AST, ALT, DMD genetic testing and the results of skeletal muscle histochemical and immunohistochemical studies, were analyzed retrospectively. Results All of the infants with BMD showed no or only slight clinical manifestations ; serum CK, AST and ALT levels were increased significantly in the infant BMD, and there was good correlation between CK levels with AST and ALT, correla- tion coefficient being （r = 0.892, P〈 0.01 ） and （r = 0.819, P〈 0.01 ）respectively; DMD genetic testing results of non frameshift deletion mutation occurred in 15 cases, accounting for 88% ; Ranging in size of muscle fibers was different, ne- crosis and regeneration of muscle fiber distribution were spotty, and fat and connective tissue were with mild hyperplasia; anti dystrophin-C, N, R antibody stained weakly ; positive or negative fibers were of patchy distribution. Conclusion Elevated serum CK and transaminase are important biochemical marker for diagnosis of infant BMD, and DMD genetic testing and dystrophin immune histochemical examination are an important means of diagnosis of infant BMD.