目的：总结42例儿童型(I～III型)脊髓性肌萎缩症(SMA)的临床与病理特征，以探讨儿童型SMA临床与病理学特征及其意义。方法：收集42例做过肌活检的SMA I～III型病例，进行临床、肌肉病理学(常规组织学及组织化学方法)分析。结果：不同型SMA临床各有特点，主要是病情轻重和起病年龄有关。起病越早者，病情越重。肌活检显示SMA I型为大组分布的圆形萎缩肌纤维，而非角形纤维，呈不完全同型肌群化，常累及整个肌束；SMA II型少见大组萎缩肌纤维，同型肌群化突出；SMA III型病理变化多样，以同型肌群化为主。结论：临床表现结合肌电图、肌活检可协助诊断儿童型脊肌萎缩症。

OBJECTIVE:To study the clinico pathologic features of childhood spinal muscular atrophy (SMA) and its significance. METHODS: The clinical and pathogic data of 42 patients with SMA Ⅰ Ⅲ were studied retrospectively. Routine histological and histochemical methods were used in muscular biopsy. RESULTS: The severity of the illness was positively related to the age of onset: the earlier the onset, the more serious the illness. There were different pathologic changes among the different types of SMA. SMA Ⅰ displayed large group round atrophic fibers and showed an incomplete type grouping; usually both type 1 and type 2 fibers were involved. The large group atrophic fibers were rarely found and the type grouping was obvious in SMA Ⅱ. The pathologic changes of SMA Ⅲ varied, and the type grouping was a major feature. CONCLUSIONS: The diagnosis of SMA could be made by combining the clinical manifestation with electroencephalography and muscular biopsy.