180例散发性神经变性病引起的痴呆朊蛋白基因突变的研究

目的对180例散发性神经变性病引起的痴呆患者进行朊蛋白基因（PRNP）突变的筛查,探讨PRNP基因突变在临床诊断的神经变性病痴呆中的发生情况以及可能的原因。方法研究180例散发性痴呆患者和310例健康对照的PRNP基因的开放阅读框架进行PCR扩增,产物直接测序,异常者重复测序,并与对照组对比。结果共发现4个不同的PRNP基因杂合突变,分别为$97N、F198V、R208C和M232R,突变率2．22％,结合患者的临床表型,以及未在310个正常人中发现突变,考虑这4例突变可能为病理性突变。结论4例突变中有3例为新突变,4例突变均可能与痴呆的发生相关。     

162例散发性阿尔茨海默病朊蛋白基因突变的研究

目的:在162例散发性阿尔茨海默病(Alzheimer's disease,AD)患者中进行朊蛋白基因(PRNP)突变的筛查,探讨PRNP基因突变在临床诊断的AD中的发生情况以及可能的原因。方法:研究对象包括162例散发性AD患者和310例健康对照。对研究对象的PRNP基因的开放阅读框架进行PCR扩增,产物直接测序,异常者重复测序,并与对照组对比。结果:共发现3个不同的PRNP基因杂合突变,分别为S97N、F198V和R208C,突变率1.85%,结合患者的临床表型,以及未在310个正常人中发现突变,考虑这3例突变可能为病理性突变。结论:3例突变均为新突变,可能与痴呆的发生相关。     

遗传性CJD一家系随访分析

目的随访一个遗传性朊蛋白病的家系,对全部家系成员进行朊蛋白基因(PRNP)突变的筛查,探讨患病者的表型和突变发生率。方法研究对象包括28例家系成员和310例健康对照。对研究对象的PRNP基因的开放阅读框架进行PCR扩增,产物直接测序,异常者重复测序,并与对照组对比。收集新发病例的影像和神经电生理资料。结果共发现15例G114V基因突变者,其中3例发病,12例为携带者。1例新发病的患者表现为进行性痴呆、肌阵挛、帕金森综合征,头颅MRI示左侧颞叶轻度萎缩,脑电图有典型的周期性放电。结论本家系为常染色体显性遗传的家族性CJD,新发病例的出现进一步明确了这一表型诊断,部分携带者不发病提示存在不完全外显。     

国人Creutzfeldt—Jakob病PrP基因表达变化的研究

目的探讨国人朊病毒病PrP基因变异与临床病理变化的关系及同欧亚病例的对比。方法取5例散发型Creutzfeldt－Jakob病（CJD）患者静脉血提取DNA，以多聚酶联反应（PCR）扩增PrP基因，用7种限制性内切酶酶切密码子102、105、129、145、178、180、200、219和232位点及DNA序列测定，并设14例非CJD痴呆和16例健康人为对照。结果发现3组中各1例具密码子129多态性，为缬氨酸／甲硫氨酸杂合子，其余均为甲硫氨酸纯合子，无缬氨酸129纯合子。结论国人CJD患者PrP基因变异及其相关的临床特征与欧洲患者不同。     

7例散发性Creutzfeldt-Jakob病患者的PRNP和APOE基因突变/变异检测及其临床意义

目的探讨散发性Creutzfeldt-Jakob病(CJD)与朊蛋白(PRNP)基因、载脂蛋白E(APOE)基因突变/变异的关系。方法对临床很可能的7例CJD患者的PRNP基因的开放阅读框架及APOE基因第四外显子进行PCR扩增,产物直接测序,异常者重复测序。结果发现1例患者存在PRNP基因E200K杂合突变,6例患者为PRNP基因129基因型MM,1例患者存在APOE基因ε4等位基因。结论 PRNP基因E200K突变为CJD致病性突变,129MM基因型与散发性CJD易感性相关,APOE基因ε4等位基因可能与散发性CJD进展有关。     

遗传性朊蛋白病一家系的临床、病理和基因突变分析

目的报道常染色体显性遗传家族性朊蛋白病一家系的基因突变，并分析先证者的临床表现、神经影像和脑活体组织检查病理改变。方法收集一个家族性痴呆家系中先证者的病史、临床表现、视频脑电图、头颅CT和头颅MRI资料；先证者在知情同意下经立体定向行脑活体组织检查术，取右额叶皮质，观察HE染色和免疫组织化学改变；提取外周血白细胞DNA，PCR直接测序，分析先证者和家族部分成员的朊蛋白基因（PRNP）异常，以150名健康志愿者为对照组检验该基因异常是否为单核苷酸多态性。结果先证者的临床表现、神经影像、脑电图和脑活体组织检查病理符合朊蛋白病诊断；先证者和部分家族成员检测出PRNP基因G114V错义突变，129密码子均为甲硫氨酸／甲硫氨酸（M／M）基因型；150名健康志愿者不具有G114V突变。结论我们发现了一个常染色体显性遗传的家族性朊蛋白病的PRNP基因G114V突变，可能为病理突变。     

广东省家族性致死性失眠症一家系临床特征及基因突变分析

目的 研究广东省家族性致死性失眠症(FFI)一家系患者的临床特征以及朊蛋白基因突变检测.方法 总结来自广东的一个FFI家系2例患者的临床表现特征,应用聚合酶链反应(PCR)、DNA直接测序技术对1例患者进行朊蛋白基因突变检测.结果 先证者主要临床表现为进行性加重的睡眠障碍和行为、认知紊乱,病程后期出现肌阵挛,病程为9个月;先证者哥哥具有类似的临床表现,病程为11个月.先证者朊蛋白基因突变检测结果发现患者为朊蛋白D178N突变,第129位多态位点为甲硫氨酸纯合型.结论 典型的临床表现有助于FFI的诊断,朊蛋白基因检测有助于确诊FFI.     

TREM2新纯合突变致早发痴呆(附一家系报告及文献复习)

目的报道1例髓样细胞触发受体2(TREM2)基因纯合突变致早发、常染色体隐性遗传性痴呆病例。方法收集1例以认知损害患者的主要临床表现、影像学及家系资料,采用基因测序检测TREM2基因多态性,并结合文献复习进行分析讨论。结果患者为40岁汉族女性,其家系调查系一近亲婚配家系,患者临床表现为进行性认知损害、个性改变、行为异常,影像学检查显示骨骼轻微累及。基因测序提示TREM2外显子区域一处纯合突变(c.391+1GA)。Minigene报告基因分析:此突变干扰基因剪接,导致氨基酸剪切改变。TREM2基因突变与散发性行为变异型额颞叶痴呆及阿尔茨海默病有关。TREM2纯合突变可导致Nasu-Hakola病,临床表现为早发、常染色体隐性遗传性痴呆,伴随早期多发骨囊肿及病理性骨折;亦可导致无骨质累及的额颞叶痴呆。结论早发、家族性中国汉族痴呆患者,遗传学筛查应纳入TREM2基因检测。     

中国汉族早发型帕金森病人群PARK2基因突变的多态性分析

目的 观察散发性早发帕金森病(Parkinson s disease, PD)患者遗传易感基因突变的形式和分布,探讨易感基因突变在PD发病中的可能作用。 方法　病例组由30例散发性早发帕金森患者组成。抽取病人外周血提取DNA,以基因组DNA为模板, 通过PCR扩增PARK2基因的第1、4、6、7号外显子。比对PCR产物测序后的突变情况。结果 发现样本中存在突变,在正常人中存在单核苷酸多态性(single nucleotide polymorphism, SNP)。结论　PARK2基因外显子的突变是我国散发性早发PD患者的致病原因之一。     

中国汉族早发型帕金森病人群PARK2基因突变的多态性分析

目的 观察散发性早发帕金森病(Parkinson s disease, PD)患者遗传易感基因突变的形式和分布,探讨易感基因突变在PD发病中的可能作用。 方法　病例组由30例散发性早发帕金森患者组成。抽取病人外周血提取DNA,以基因组DNA为模板, 通过PCR扩增PARK2基因的第1、4、6、7号外显子。比对PCR产物测序后的突变情况。结果 发现样本中存在突变,在正常人中存在单核苷酸多态性(single nucleotide polymorphism, SNP)。结论　PARK2基因外显子的突变是我国散发性早发PD患者的致病原因之一。     

Mutation in the prion protein gene at codon 232 in Japanese patients with Creutzfeldt-Jakob disease: a clinicopathological,immunohistochemical and transmission study

We describe the clinical, neuropathological, immunohistochemical and transmission findings in three patients with Creutzfeldt-Jakob disease (CJD) with a substitution from methionine to arginine at codon 232 (M232R) in the prion protein (PrP) gene. The patients with M232R presented clinically with rapidly progressive dementia, myoclonus, and periodic synchronous discharges in the electroencephalogram. These findings were mostly consistent with those for sporadic CJD. All patients reached the stage of akinetic mutism between 2 and 6 months, and died between 4 and 24 months after the onset of the disease. Histopathological examination revealed spongiform changes, neuronal loss and severe astrocytosis. Immunohistochemical staining for PrP showed diffuse gray matter staining, including synaptic structures. However, no plaque-type PrP deposition was observed in the affected brain tissue sections. The brain homogenates from two patients were successfully transmitted to experimental animals. Since the same mutation was not found in 100 healthy control individuals, the mutation might be associated with the disease. The clinicopathological and experimental transmission studies of CJD patients with this PrP gene mutation may thus help us to determine both phenotypic variations and the potential infectivities in different forms of prion diseases. Received: 27 December 1995 / Revised, accepted: 25 March 1995     

An autopsied case of Creutzfeldt‐Jakob disease with mutation in the prion protein gene codon 232 and type 1+2 prion protein

A 68‐year‐old Japanese man gradually showed abnormal behavior and gait disturbance with bradykinesia. Slowly progressive dementia, including memory disturbance and disorientation, was also observed. Cerebral cortical hyperintensity on diffusion‐weighted MRI was observed 6 months after onset. The patient progressed to an akinetic mutism state with mild myoclonus, and atypical periodic sharp‐wave complexes were observed by electroencephalogram 13 months after onset. He was clinically suspected of having atypical CJD and died after 19 months total disease duration. The brain weighed 1160 g and showed mild atrophy of the cerebrum and cerebellum with ventricular dilatation. Spongiform changes with varying vacuole size and gliosis was extensive in the cerebral cortex and basal ganglia. Neuron loss in the cerebral cortex, basal ganglia and thalamus was relatively mild. The cerebellum showed mild spongiform changes of the molecular layer and mild neuron loss in the Purkinje cell layer. PrP immunostaining showed mainly coarse‐type combined with diffuse synaptic‐type PrP deposition in the cerebral gray matter. Some perivacuolar‐type PrP deposition was also present. Numerous plaque‐type PrP depositions were observed in the molecular layer of the cerebellum. Analysis of the PrP gene revealed a methionine‐to‐arginine (Met‐to‐Arg) substitution at codon 232 (M232R) with Met homozygosity at codon 129. Western blot analysis of protease‐resistant PrP indicated type 2 dominant PrP combined with type 1. Genetic CJD with M232R substitution in the PrP gene has only been reported in Japan. Although two clinical phenotypes (rapid‐type and slow‐type) were suggested in the M232R CJD cases (despite the presence of the same PrP genotype), the pathological and molecular backgrounds have not been well understood because there have only been a few autopsied case reports. This is the first case report of M232R CJD presenting with 1 + 2 PrP.     

An inherited prion disease with a PrP P105L mutation: clinicopathologic and PrP heterogeneity.

OBJECTIVE: To clarify a clinical and neuropathologic phenotype of an inherited prion disease associated with a missense mutation at codon 105 in the prion protein (PrP) gene that was originally described as a variant of Gerstmann-Str?ussler-Scheinker disease demonstrating spastic paraparesis. METHODS: Two siblings from a Japanese family are described. PrP gene analyses, neuropathologic studies with immunohistochemistry, and Western blot analysis of the PrP were performed. RESULTS: Both patients showed a missense (proline-->leucine) mutation at codon 105 and a methionine/valine polymorphism at codon 129 of the PrP gene. Clinically, Patient 1 presented with progressive spastic paraparesis, ataxia, and dementia. Patient 2, the sister of Patient 1, showed prominent action myoclonus and dementia. Neuropathologically, multiple PrP-positive amyloid plaques and diffuse PrP deposition in the deep cortical layers were found in the cerebral cortex with primarily frontal dominant atrophy in both patients. Tau-positive pathologic structures including neurofibrillary tangles, neuropil threads, and dystrophic neurites around the plaques were abundant in the brain of Patient 2. In contrast, the tau pathology was scarce in Patient 1. Western blot analysis of the brain showed different patterns of detergent-insoluble PrP fragments between the patients. CONCLUSIONS: Despite the identical codon 105 mutation and codon 129 polymorphism of the PrP gene, remarkable clinical and neuropathologic differences, and PrP heterogeneity were present between the affected siblings. The phenotypic variability might be related to PrP heterogeneity.     

A patient with dementia with Lewy bodies and codon 232 mutation of PRNP

The authors describe a patient who had a point mutation at codon 232 of the prion protein gene, resulting in the substitution of methionine for arginine (M232R). The patient developed dementia and died 6 years after its onset. Autopsy revealed dementia with Lewy bodies, not Creutzfeldt-Jakob disease. Although the M232R mutation has been reported to cause Creutzfeldt-Jakob disease, findings in our patient suggest that not all patients presenting progressive dementia with M232R mutation have Creutzfeldt-Jakob disease.     

Distribution of prion protein in German patients with Creutzfeldt-Jakob disease is different from that in Japanese patients

We investigated the distribution of prion protein (PrP) in 14 German patients with sporadic Creutzfeldt-Jakob disease (CJD) and compared it with that observed in Japanese patients. Immunohistochemical study revealed diffuse gray matter stainings including synaptic structures in all cases. In addition, 4 patients showed plaque-type deposition which was very rarely observed among sporadic Japanese patients without known mutation of the PrP gene but with valine at codon 129. A higher incidence of PrP plaques in German sporadic CJD may be related to the racial difference in the PrP gene.     

Distinctive cerebellar immunoreactivity for the prion protein in familial (E200K) Creutzfeldt-Jakob disease

We have compared the immunomorphological spectrum of the deposition of the disease-associated prion protein (PrP(Sc)) in the cerebral and cerebellar cortex of 32 Creutzfeldt-Jakob disease (CJD) patients with the PrP gene (PRNP) E200K mutation to 45 sporadic CJD and 14 other genetic prion disease cases. PrP deposits correlate with the genotype at the methionine/valine (MV) polymorphic codon 129. While the diffuse/synaptic and patchy/perivacuolar PrP deposits and PrP plaques have a similar distribution and correlation with the genotype at codon 129 as in sporadic CJD, an additional peculiar PrP immunostaining pattern occurs in the cerebellum in 81% E200K mutation brains including 93% of M129M, 71% of M129V, but not in the single V129V case. It is localized to the molecular layer and consists of coarse granular PrP deposits arranged in a stripe-like manner predominantly perpendicular to the surface, closely resembling the parasagittal arborization of climbing fibers. Our results suggest that (1) the type of PrP deposits in the cerebellum may suggest genetic disease and the need for genetic testing; and (2) the peculiar stripes of PrP deposits might reflect selective vulnerability of cerebellar structures.     

A novel phenotype in familial Creutzfeldt-Jakob disease: prion protein gene E200K mutation coupled with valine at codon 129 and type 2 protease-resistant prion protein.

A novel phenotype of familial Creutzfeldt-Jakob disease (CJD) with mutated codon 200 of the prion protein gene (PRNP) coupled with the valine codon 129 (E200K-129V haplotype) has two features never observed in subjects carrying the pathogenic mutation coupled with the methionine codon 129 (E200K-129M haplotype): (1) plaque-like prion protein (PrP) deposits in the cerebellum and (2) type 2 protease-resistant prion protein (PrP(res)). This observation further underlines the role of codon 129 on the mutated PRNP allele in modulating the phenotype of familial prion diseases.     

Basis of phenotypic variability in sporadic Creutzfeldt-Jakob disease

OBJECTIVE: To determine the correlation of clinical and pathologic features with prion protein (PrP) gene polymorphism at codon 129 and with biochemical characteristics of the protease-resistant PrP (PrPres) in sporadic Creutzfeldt-Jakob disease (CJD). METHODS: Clinical data acquisition, determination of the codon 129 genotype of the PrP gene, brain pathologic study, and immunoblot analysis of crude brain extracts were carried out in 14 patients. RESULTS: The first group of 10 subjects showed the classic clinical triad, with dementia, myoclonus, and periodic sharp waves on EEG. None of the subjects had amyloid plaques, but PrP immunoreactivity was of diffuse synaptic type in the cerebellar cortex. All subjects were methionine-methionine at codon 129 and the PrPres had a biochemical profile of type 1 (unglycosylated band of 21.5 kD). A second group of three patients showed cerebellar ataxia and later dementia. Periodic sharp waves on EEG were absent. PrP amyloid plaques predominated in the cerebellar cortex, along with diffuse PrP immunoreactivity. These subjects were valine-valine at codon 129 and had a type 2 PrPres (unglycosylated band of 19.4 kD). In the last patient cerebellar ataxia and dementia appeared simultaneously. Many Kuru-type plaques were present in the cerebellar cortex; many PrP amyloid plaques were present in the basal ganglia. This patient was methionine-valine at codon 129 and the PrPres was of type 1. CONCLUSIONS: The codon 129 genotype is only one of the factors determining CJD phenotype, and the biochemical pattern of PrP has no direct correlation with this phenotype.     

散发性Creutzfeldt-Jakob病患者10例prion基因研究

目的 检测10例Creutzfeldt-Jakob病（CJD）患者prion基因（PRNP）外显子突变情况.方法 抽取患者外周静脉血,提取DNA,PCR法扩增PRNP外显子后直接测序,并用限制性内切酶Nsp Ⅰ检测PRNP 129位点密码子基因型.结果 2例肯定CJD患者中,1例PRNP检测未见异常,另1例PRNP第729碱基G被C取代（729G→C）,使编码prion第211个氨基酸的密码子GAG变成了GAC,翻译后第211个氨基酸由谷氨酸变为天冬氨酸（E211D）.8例很可能CJD患者中,2例PRNP第751碱基G被A取代（751G→A）,使编码prion第219个氨基酸的密码子GAG变成了AAG,翻译后第219个氨基酸由谷氨酸变为赖氨酸（E219K）.10例CJD患者PRNP 129位点密码子基因型都是甲硫氨酸纯合型.结论 1例肯定CJD患者的prion基因外显子存在一种新的点突变E211D,这很可能是导致遗传prion病发生的原因.2例很可能CJD患者的prion基因突变E219K,与M129V同属于基因多态性,而不是致病原因.prion基因检测有助于prion病的诊断.