脊髓小脑性共济失调12亚型的基因特点、脑白质微细结构损害影像学特点、血浆α-突触核膜蛋白表达水平的研究

发布时间：2018-05-01 04:30

本文选题：脊髓小脑共济失调 + 三核苷酸重复　；参考：《新疆医科大学》2014年博士论文

【摘要】：目的：1）研究新疆地区维吾尔族脊髓小脑性共济失调12亚型（SCA12）致病基因的CAG三核苷酸病理重复次数范围及临床特点；2）通过测量表观扩散系数（ADC）、各向异性分数（FA）两个指标研究脊髓小脑性共济失调12亚型脑白质微细结构损害的影像学特点；3）探讨新疆维吾尔族带有帕金森症状的遗传性脊髓小脑型共济失调12型的发病是否与帕金森病的发病有共同的发病基础，，是否由α-突触核蛋白异常聚集所致。方法：1）依据Harding标准，我们针对一个2年前经基因诊断确诊为SCA12亚型的维吾尔族家系，进行跟踪随访，应用聚合酶链反应、琼脂糖凝胶电泳、T载体分子克隆技术并结合酶切鉴定等技术对其中13例患者、54例家系“健康”个体进行分子遗传学诊断，同时对致病基因CAG三核苷酸病理重复次数进行突变分析；2）针对一个经基因诊断为SCA12亚型的家系成员，包括13例患者，5个症状前患者，通过磁共振扩散张量的两个指标：表观扩散系数（ADC）、各向异性分数（FA），选择测量感兴趣区域：脑桥、小脑上脚、小脑中脚、小脑蚓部、大脑皮层、小脑半球进行测量；3）经基因诊断SCA12患者13人，家系症状前患者5人，正常28人进行酶联免疫吸附试验（ELISA法）测量血浆α-突触核蛋白浓度。结果：1）发现该家系SCA12型患者13例，症状前患者5例。患者CAG重复数目范围为48 54次；症状前患者CAG重复数目范围为49 52次。正常人PPP2R2B基因CAG重复数目范围为9 16次。SCA12患者CAG序列重复次数与SARA评分两变量呈正相关关系（0.708，P＜0.05）；2）和对照组相比，SCA12亚型患者在小脑皮层、小脑上脚、大脑皮层、小脑蚓部区域ADC值上升；SCA12亚型患者在小脑皮层，症状前患者在小脑皮层、小脑蚓部的FA值明显降低。病程、共济失调量表评分、小脑蚓部的ADC值之间具有高度正相关；3）SCA12患者组与症状前患者组、正常对照组三组α-突触核蛋白表达水平不完全相同（P＜0.05），SCA12患者组浓度的总体平均值最高。但是SCA12患者发病年龄、病程与α-突触核蛋白浓度无相关关系。结论：1）患者病程越长，CAG重复数目越高，SARA评分越高，共济失调患者的病情越严重。SCA12型的48次CAG病理重复次数为国内外报道的最小CAG病理重复次数；此发现进一步缩短了正常与异常重复次数之间的差距。对维吾尔族SCA12型的基因突变特点进行分析，从而对于该类疾病的准确分类、病因探讨、治疗、产前诊断等具有重要的意义；2）SCA12亚型患者脑白质微细结构存在损害；SCA12症状前患者脑白质微细结构损害可能最早在小脑皮层、小脑蚓部发生。小脑蚓部的ADC值可能成为反映SCA12患者共济失调严重程度、认知障碍程度的一个重要量化指标；3）带有帕金森症状的SCA12型α-突触核蛋白的表达水平升高，可能和帕金森病存在着共同的发病基础。检测带有帕金森症状的SCA12患者的α-突触核蛋白可能作为评估疾病严重程度的较为敏感的一个生物学指标。
[Abstract]:Objective: to study the range and clinical characteristics of CAG trinucleotides (CAG trinucleotide repeat) in Uygur patients with spinal cerebellar ataxia subtype 12 (SCA12) in Xinjiang. Objective to study the imaging features of microstructural damage in white matter of cerebellar ataxia 12 subtype of spinal cord. (3) to explore whether the incidence of hereditary spinal cerebellar ataxia 12 with Parkinson's symptoms in Xinjiang Uygur is associated with Parkin. The incidence of Sentinia has a common basis. Whether it is caused by abnormal aggregation of 伪-synaptophysin. Methods according to Harding criteria, we followed up a Uygur family with SCA12 subtype diagnosed by gene diagnosis 2 years ago and used polymerase chain reaction (PCR). The molecular cloning technique of T-vector by agarose gel electrophoresis and restriction endonuclease identification were used to diagnose the molecular genetics of 54 healthy individuals from 54 families of 13 patients. At the same time, the number of pathological repeats of the pathogenic gene CAG trinucleotide was analyzed for a family member diagnosed by gene as SCA12 subtype, including 13 patients and 5 presymptomatic patients. Diffusion of Zhang Liang by magnetic resonance: apparent diffusion coefficient (Zhang Liang), anisotropic fraction (FAA), measurement of areas of interest: pontine, superior cerebellar foot, middle cerebellar foot, cerebellar vermis, cerebral cortex, The plasma levels of 伪 -synaptophysin were measured in 13 patients with SCA12 diagnosed by gene, 5 patients with pre-symptomatic disease and 28 normal subjects by enzyme-linked immunosorbent assay (Elisa). Results (1) 13 cases of SCA12 type and 5 cases of pre-symptomatic patients were found in this pedigree. The number of CAG repeats in patients ranged from 48 to 54, and that of CAG from pre-symptom to pre-symptom was 49 and 52. The number of CAG repeats of PPP2R2B gene in normal subjects ranged from 9 to 16 times. The number of CAG repeats in patients with SCA12 was positively correlated with the two variables of SARA score (P < 0. 05, P < 0. 05) compared with the control group, the patients with subtype SCA12 were in the cerebellar cortex, superior cerebellar foot, and cerebral cortex. The ADC value of cerebellar vermis region increased and the FA value of SCA12 subtype patients decreased significantly in cerebellar cortex, presymptomatic patients in cerebellar cortex and cerebellar vermis. There was a high positive correlation between the ADC values of cerebellar vermis and presymptomatic patients, and the average of 伪 -synaptophysin expression in the three groups of normal control group was not exactly the same (P < 0.05). The average value of 伪 -synaptic protein expression was the highest in the three groups (P < 0.05). However, there was no correlation between the age and course of SCA12 and the concentration of 伪-synaptophysin. Conclusion (1) the longer the course of disease, the higher the number of CAG repeats and the higher the score of SARA, the more serious the condition of patients with ataxia. The 48 CAG pathological repeats of type SCA12 are the minimum number of CAG pathological repeats reported at home and abroad. This finding further shortens the gap between normal and abnormal repetition times. The characteristics of SCA12 gene mutation in Uygur nationality were analyzed, and the classification, etiology and treatment of the disease were discussed. Prenatal diagnosis is of great significance in the diagnosis of white matter microstructures in the white matter of patients with SCA12 subtype. Before SCA12 symptoms, the white matter microstructures in patients with SCA12 may occur at the earliest in the cerebellar cortex and cerebellar vermis. The ADC value of cerebellar vermis may be an important quantitative index to reflect the severity of ataxia and cognitive impairment in patients with SCA12. (3) the expression of SCA12 type 伪 -synaptophysin with Parkinson's symptoms is increased. There may be a common pathogenesis with Parkinson's disease. The detection of 伪-synaptophysin in SCA12 patients with Parkinson's symptoms may be a sensitive biological marker for evaluating the severity of the disease.
【学位授予单位】：新疆医科大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：R744.7

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