Abstract: Objective To analyze the early clinical features of spinal muscular atrophy type Ⅰ (SMA-Ⅰ). Method Early clinical features and relative assistant examinations of six children with SMA-Ⅰ diagnosed in Foshan Maternal and Child Health Care Hospital from Oct.2015 to Oct.2016 were retrospectively analyzed. Results Gene detection of six children showed homozygous deletion of exon 7,8 of the SMN1 gene,with only 2 copies of SMN2 gene.All children presented with profound weakness of the trunk and limbs,poor head control,lack of active movement,severe hypotonia,absent tendon reflexes,and low crying voice.However,swallowing weakness and feeding intolerance were not obvious before 2 to 3- moth -old infants.Some children were born with joint contracture.Neonatal behavioral neurological assessment (NBNA) was carried out to four of six children.And the total score of NBNA was significantly lower than that of normal level. Conclusions Profound weakness of the trunk and limbs,low crying voice are typical clinical features of SMA-Ⅰ children at the early stage.SMN gene detection should be applied to children with very low NBNA total scores.

Key words: spinal muscular atrophy type Ⅰ, early, clinical feature, neonatal behavioral neurological assessment

摘要： 目的 分析婴儿型脊肌萎缩症(Ⅰ型SMA)患儿的早期临床特征,为早期诊断提供线索。方法 对2015年10月-2016年10月在佛山市妇幼保健院被确诊的Ⅰ型SMA6例临床表现和相关辅助检查进行了回顾性分析。结果 6例患儿均为SMN1基因7号和8号外显子纯合缺失,SMN2基因均为2个拷贝数。临床表现为全身松软无力、不能抬头、四肢主动活动少、肌张力严重低下、腱反射未引出,出生1个月内哭声由响亮变成低下,2～3月龄内无明显吞咽障碍、喂养困难表现,部分患儿出生时即有双侧腕关节下垂。辅助检查方面,4例患儿行新生儿行为神经测定(NBNA),总分显著低于正常水平。结论 躯干及四肢肌肉松软无力、哭声低下是Ⅰ型SMA患儿的早期临床特征,对于NBNA总分显著低下,且认知行为正常者,应行基因检查以进一步明确诊断。

关键词: I型脊肌萎缩症, 早期, 临床特征, 新生儿行为神经测定