儿童脊肌萎缩症运动神经元生存基因缺失分析

目的评价聚合酶链反应-限制性片段长度多肽性（PCR-RFLP）分析技术在脊肌萎缩症（SMA）临床诊断中的价值，分析端粒侧运动神经元生存基因（SMNt）表达与SMA临床分型之间的关系。方法对临床拟诊为SMA的23例患儿同时采用临床诊断标准和PCR-RFLP分析技术进行诊断，两种结果对比，分析灵敏度、特异度、Kappa值及P值。结果（1）临床诊断与PCR-RFLP基因诊断结果比较：23例拟诊患儿中临床确诊为SMA者18例，非SMA者5例。PCR-RFLP技术检测结果：5例非SMA者，SMNt基因检测均无缺失；18例确诊SMA者，SMNt基因缺失者15例，无SMNt基因缺失者3例，缺失频率为83．3％。此方法的灵敏度为83．3％，特异度为100％，阳性预测值100％，阴性预测值62．5％，真实性为86．96％，Kappa值为0．685。（2）SMA不同临床分型中SMNt基因7、8号外显子缺失检测结果：Ⅰ型患者以7、8号外显子缺失为主，SMNt基因缺失频率100．0％；Ⅲ型患者以7号外显子缺失为主，SMNt基因缺失频率为66．7％；Ⅰ型患者7、8号外显子联合缺失频率较Ⅲ型高（P〈0．05）。结论（1）PCR-RFLP分析技术简便、快捷、特异性高，敏感性好，适用于临床儿童型SMA的基因诊断，尤其对于SMAI型患者。（2）SMNt基因7、8号外显子联合缺失常常提示病情严重，预后不良；单独缺失提示病情较轻，预后较好。

Deletions of SMNt Gene in the Children with Spinal Muscular Atrophy

Objective To assess the diagnostic value of Polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP)in children with spinal muscular atrophy and analyze the relation between telomeric portion of survival motor neuron gene expression and the types of SMA in terms of clinical.Methods Twenty-three children with suspicion of spinal muscular atrophy in terms of clinical features were simultaneously diagnosed by gold standard and PCR-RFLP.The results from two methods were compared by the sensi...