摘要
目的对疑诊为脊肌萎缩症（SMA）患者的运动神经元存活基因SMNl进行缺失分析，探讨基因诊断对SMA的临床应用价值。方法采用PCR和限制性片段长度多态性（PCR—RFLP）技术，对2007年1月至2014年12月于云南省第一人民医院遗传诊断中心和昆明医科大学第四附属医院神经内科就诊的154例SMA疑诊患者和20名健康体检者进行SMN1基因外显子7和外显子8缺失检测，统计上述基因的缺失频率，采用SPSS13．0软件对各缺失类型在不同SMA型别间的差异进行显著性检验。结果154例疑诊患者中，101例检出SMN1基因外显子7纯合缺失，基因诊断率为65．6％（101／154）。101例SMNl基因纯合缺失病例中，外显子7和8均纯合缺失为98例，占97．0％（98／101）；3例仅外显子7纯合缺失，占3．0％（3／101）；未见外显子8的单独缺失。基因诊断阴性患者经过临床随访，其中4例可维持SMA的诊断，105例SMA确诊患者中I型68例，Ⅱ型27例，Ⅲ型10例，分别占64．8％（68／105）、25．7％（27／105）和9．5％（10／105），未发现Ⅳ型SMA。20名健康体检者未检出SMN1基因外显子7和8缺失。结论PCR—RFLP技术对于诊断SMA患者具有无创性、简单、灵敏度和特异性较高的特点，可作为疑诊SMA患者的首选诊断和排除诊断方法；强化SMA临床诊断标准并对基因诊断阴性的疑诊患者进行重新评估，将有助于提高临床诊断的准确率和检出率。
Objective To explore the clinical value of genetic diagnosis of SMA, the homozygous deletion of survival motor neuron 1 （ SMN1 ） gene in suspected spinal muscular atrophy （SMA） patients were analyzed in this study. Methods A total of 154 patients suspected with SMA and 20 healthy volunteers were recruited from January 2007 to December 2014 in the Genetic Diagnosis Center of the First People＇s Hospital of Yunnan Province and the Department of Neurology of the Fourth Affiliated Hospital of Kunming Medical University. Potential deletions in exons 7 and 8 of SMN1 gene were screened by use of polymerase chain reaction and restriction fragment length polymorphism （PCR-RFLP） method in both 154 patients suspected with SMA and 20 healthy volunteers. The frequencies of the deletions in exons 7 and 8 of SMN1 were calculated and statistical analysis of different deletion types among 3 SMA groups was performed with SPSS 13.0 software package. Results Among 154 suspected SMA patients, 101 cases with homozygous deletions of exon 7 of SMN1 gene were detected, which accounted 65.6% （101/154） of the suspected SMA patients. Among the 101 SMA patients, 97.0% （98/101） of the patients with both homozygous deletions of exons 7 and 8 for SMN1 gene and 3.0% （3/101） of the patients with homozygous deletions of only exon 7 for SMN1 gene were detected. The patient with only deletion of exon 8 for SMN1 gene was notdeteeted. Four cases with negative results were subjected to be followed-up, but they were characteristic of SMA symptom by clinical re-visit. Thus, total 105 patients were confirmed with SMA, among them, 68 were type I SMA, 27 were type Ⅱ SMA, and 10 were type Ⅲ SMA, which accounted for 64. 8% （68/105）, 25.7% （27/105） and 9. 5% （10/105） of the SMA patients, respectively. Type Ⅳ SMA was not observed in these patients. No deletion was detected among 20 healthy volunteers. Conclusions PCR-RFLP assay is a noninvasive, simple, high sensitive and specific method for SMA diagnosis, which can be considered as the first-line genetic test for the suspected SMA patients. It will help to improve the accuracy of clinical diagnosis and the detection rate by strengthening the clinical diagnostic criteria and re-evaluating the suspected patients after negative genetic diagnosis.
出处
《中华检验医学杂志》
CAS
CSCD
北大核心
2015年第12期833-837,共5页
Chinese Journal of Laboratory Medicine
基金
云南省科技厅-昆明医科大学联合基金（2012FB079）
云南省卫生系统领军人才基金（L-201201）
关键词
肌萎缩
脊髓性
运动神经元生存蛋白质1
聚合酶链反应
多态性
限制性片段长度
Muscular atrophy, spinal
Survival of motor neuron 1 protein
Polymerase chain reaction
Polymorphism, restriction fragment length
