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.     

Sporadic Creutzfeldt-Jakob disease with MM1-type prion protein and plaques

The authors report a 75-year-old woman with atypical sporadic Creutzfeldt-Jakob disease (CJD) characterized by MM1-type prion protein (PrP) (methionine homozygosity at codon 129 in the PrP gene and type-1 protease-resistant PrP) and PrP plaques. This patient is the first case of sporadic CJD with plaque-forming MM1-type PrP, suggesting either a shared prion strain with the plaque-forming subset of dural graft-associated CJD or shared host genetic factors that are unrelated to the PrP genotype.     

Prion diseases, update]

In prion diseases, genotypic classification has been useful to understand the clinical course and pathological changes. However, among patients with the same prion protein (PrP) genotype, there are variations in the pathological and clinical phenotype. Recently, PrP typing was proposed by the molecular weight of protease-resistant PrP (PrPres). Combined with genotype and PrPres typing, sporadic Creutzfeldt-Jakob disease (CJD) could be classified precisely. In addition, we found the fragmented PrP molecules to differentiate between dura-classic CJD and dura-plaque type CJD. We report herein that the fragmented PrP is a useful marker to classify human prion diseases, and also a clue to analyze abnormal PrP structures. The fragmented PrP was detected in patients with classic-type CJD, sporadic thalamic-type CJD, familial CJD with codon 200 or 232 mutation, or familial Gerstmann-Straussler syndrome (GSS) with codon 102 mutation. Among patients with type-1 abnormal PrP, the transmission study was successful in sporadic CJD with type 1 PrPres and the fragment PrP, but not in CJD without the fragmented PrP. Thus, in the prion field, type-specific PrP structure contributes to the clinicopathology and transmissibility.     

Neuropathological and biochemical criteria to identify acquired Creutzfeldt‐Jakob disease among presumed sporadic cases

As an experimental model of acquired Creutzfeldt‐Jakob disease (CJD), we performed transmission studies of sporadic CJD using knock‐in mice expressing human prion protein (PrP). In this model, the inoculation of the sporadic CJD strain V2 into animals homozygous for methionine at polymorphic codon 129 (129 M/M) of the PRNP gene produced quite distinctive neuropathological and biochemical features, that is, widespread kuru plaques and intermediate type abnormal PrP (PrP^Sc). Interestingly, this distinctive combination of molecular and pathological features has been, to date, observed in acquired CJD but not in sporadic CJD. Assuming that these distinctive phenotypic traits are specific for acquired CJD, we revisited the literature and found two cases showing widespread kuru plaques despite the 129 M/M genotype, in a neurosurgeon and in a patient with a medical history of neurosurgery without dura mater grafting. By Western blot analysis of brain homogenates, we revealed the intermediate type of PrP^Sc in both cases. Furthermore, transmission properties of brain extracts from these two cases were indistinguishable from those of a subgroup of dura mater graft‐associated iatrogenic CJD caused by infection with the sporadic CJD strain V2. These data strongly suggest that the two atypical CJD cases, previously thought to represent sporadic CJD, very likely acquired the disease through exposure to prion‐contaminated brain tissues. Thus, we propose that the distinctive combination of 129 M/M genotype, kuru plaques, and intermediate type PrP^Sc, represents a reliable criterion for the identification of acquired CJD cases among presumed sporadic cases.     

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.     

Genetic Creutzfeldt-Jakob disease associated with the E200K mutation: characterization of a complex proteinopathy

The E200K mutation is the most frequent prion protein gene (PRNP) mutation detected worldwide that is associated with Creutzfeldt-Jakob disease (CJD) and thought to have overlapping features with sporadic CJD, yet detailed neuropathological studies have not been reported. In addition to the prion protein, deposition of tau, ??-synuclein, and amyloid-?? has been reported in human prion disease. To describe the salient and concomitant neuropathological alterations, we performed a systematic clinical, neuropathological, and biochemical study of 39 individuals carrying the E200K PRNP mutation originating from different European countries. The most frequent clinical symptoms were dementia and ataxia followed by myoclonus and various combinations of further symptoms, including vertical gaze palsy and polyneuropathy. Neuropathological examination revealed relatively uniform anatomical pattern of tissue lesioning, predominating in the basal ganglia and thalamus, and also substantia nigra, while the deposition of disease-associated PrP was more influenced by the codon 129 constellation, including different or mixed types of PrP^res detected by immunoblotting. Unique and prominent intraneuronal PrP deposition involving brainstem nuclei was also noted. Systematic examination of protein depositions revealed parenchymal amyloid-?? in 53.8%, amyloid angiopathy (A??) in 23.1%, phospho-tau immunoreactive neuritic profiles in 92.3%, neurofibrillary degeneration in 38.4%, new types of tau pathology in 33.3%, and Lewy-type ??-synuclein pathology in 15.4%. TDP-43 and FUS immunoreactive protein deposits were not observed. This is the first demonstration of intensified and combined neurodegeneration in a genetic prion disease due to a single point mutation, which might become an important model to decipher the molecular interplay between neurodegeneration-associated proteins.     

A novel phenotype of sporadic Creutzfeldt-Jakob disease

An atypical case of sporadic Creutzfeldt-Jakob disease (CJD) is described in a 78-year-old woman homozygous for methionine at codon 129 of the prion protein (PrP) gene. The neuropathological signature was the presence of PrP immunoreactive plaque-like deposits in the cerebral cortex, striatum and thalamus. Western blot analysis showed a profile of the pathological form of PrP (PrP(Sc)) previously unrecognised in sporadic CJD, marked by the absence of diglycosylated protease resistant species. These features define a novel neuropathological and molecular CJD phenotype.     

Inherited prion disease caused by the V210I mutation: transmission to transgenic mice.

OBJECTIVE: To describe the clinical and neuropathologic profile and determine the strain characteristics of familial Creutzfeldt-Jakob disease (fCJD) caused by a point mutation of the PRNP gene at codon 210 that results in a valine-to-isoleucine substitution in the prion protein (PrP). METHODS: The clinicopathologic features of four individuals from the United States who died of fCJD(V210I) were compared. Transgenic (Tg) mice expressing a chimeric human-mouse PrP transgene were inoculated with brain extracts from three fCJD(V210I) cases, sporadic CJD (sCJD), fCJD(E200K), and fatal familial insomnia (FFI), to compare prion strain characteristics. RESULTS: The clinicopathologic profile of fCJD(V210I) was variable among cases but shared similarities with sCJD. The pattern of PrP(Sc) deposition in the brains of Tg mice was similar to that caused by sCJD but different from that associated with fCJD(E200K) or FFI. CONCLUSIONS: Each of these prion diseases is characterized by a rapidly progressive dementia with myoclonus, periodic complexes on EEG, and spongiform change without PrP plaque deposition in the brain. The occurrence of a different PrP(Sc) phenotype with each PRNP mutation argues that each respective amino acid sequence substitution produces a different prion strain.     

Insomnia associated with thalamic involvement in E200K Creutzfeldt-Jakob disease

BACKGROUND: Insomnia with predominant thalamic involvement and minor cortical and cerebellar pathologic changes is not characteristic of familial Creutzfeldt-Jakob disease (CJD) but is a hallmark of fatal familial insomnia. OBJECTIVE: To report a 53-year-old woman with intractable insomnia as her initial symptom of disease. METHODS: The authors characterized clinical, pathologic, and molecular features of the disease using EEG, polysomnography, neurohistology, Western blotting, protein sequencing, and prion protein (PrP) gene (PRNP) analysis. RESULTS: The patient developed dysgraphia, dysarthria, bulimia, myoclonus, memory loss, visual hallucinations, and opisthotonos, as well as pyramidal, extrapyramidal, and cerebellar signs. Polysomnographic studies showed an absence of stages 3 and 4, and REM. She died 8 months after onset. On neuropathologic examination, there was major thalamic involvement characterized by neuronal loss, spongiform changes, and prominent gliosis. The inferior olivary nuclei exhibited chromatolysis, neuronal loss, and gliosis. Spongiform changes were mild in the neocortex and not evident in the cerebellum. PrP immunopositivity was present in these areas as well as in the thalamus. PRNP analysis showed the haplotype E200K-129M. Western blot analysis showed the presence of proteinase K (PK)-resistant PrP (PrP(sc)) with the nonglycosylated isoform of approximately 21 kd, corresponding in size to that of type 1 PrP(sc). N-terminal protein sequencing demonstrated PK cleavage sites at glycine (G) 82 and G78, as previously reported in CJD with the E200K-129 M haplotype. CONCLUSIONS: Insomnia may be a prominent early symptom in cases of CJD linked to the E200K-129M haplotype in which the thalamus is severely affected.     

A three-sister sibship of Gerstmann-Sträussler-Scheinker disease with a CJD phenotype

OBJECTIVE: To describe a rare phenotypic variant of P102L Gerstmann-Str?ussler-Scheinker disease (GSS). BACKGROUND: Classic GSS is characterized by an early age at onset, prominent cerebellar signs with a slowly evolving dementia, and a neuropathology including multifocal PrP-positive plaques and variable but usually modest spongiform change. METHODS: Clinical, neuropathologic, immunohistochemical, and molecular genetic analysis of three sisters in a Hungarian family was performed. RESULTS: The clinical course of all three sisters was indistinguishable from sporadic Creutzfeldt-Jakob disease (CJD). Neuropathologic examination revealed spongiform changes, PrP (prion)-positive unicentric "kuru" or multicentric plaques, and abundant beta-A4-positive senile plaques. Molecular genetic analysis of the PRNP gene showed the heterozygous codon P102L mutation of classic GSS, with the methionine encoding allele of a heterozygous codon 129 coupled to the mutant 102 allele. CONCLUSION: The authors report the second recorded example of a sporadic CJD phenotype occurring in association with the P102L GSS genotype, and the first instance in which the phenotype was the rule rather than the exception, or was associated with prominent beta-A4 plaque formation.     

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.     

12例散发性早发性痴呆朊蛋白基因变异的研究

目的研究12例散发性早发性痴呆患者[伴有锥体外系和(或)小脑、额叶症状]朊蛋白基因的变异。方法从患者外周血白细胞中提取基因组DNA,用多聚酶链式反应(PCR)进行朊蛋白基因的体外扩增,再用Sanger法对PCR产物进行测序分析,测序发现的变异用限制性片断长度多态性方法(RFLP)进行进一步确认。结果在12例患者中发现4种不同的朊蛋白基因杂合性变异:M 129V、E 219K、M 232R和五串联重复序列内的24个核苷酸缺失(de lR 2),其中M 232R可能是病理性突变,其余3种为基因多态性。结论与既往朊蛋白基因变异的研究相结合,考虑朊蛋白基因多态性在日本人群中相对常见,而且与朊蛋白基因突变有关的基因型-表现型的异质性关系为深入理解早发性痴呆的病因提供了新的启发。     

An atypical case of sporadic Creutzfeldt–Jakob disease with Parkinson's disease

We report here an autopsy case of a 64‐year‐old female with slowly progressive dementia and parkinsonism in a 4‐year‐long clinical course. Post‐mortem examination revealed a severely atrophic brain with spongiform degeneration, neuronal loss and gliosis in the gray matter. Many prion protein plaque deposits were present in the occipital lobe, amygdala and cerebellum. Additionally, Lewy bodies were observed in the brainstem. Prion protein gene analysis of the patient revealed polymorphism at the codon‐129 valine heterozygote. This genotype is known to sometimes accompany a missense mutation of the gene in uncommon hereditary prion diseases, but no mutation was found in the open reading frame. Thus, it might be suggested that this case showed simultaneously the features of both sporadic Creutzfeldt‐Jakob disease (CJD) with codon‐129 valine and Parkinson's disease. However, the predisposing factors for contracting both diseases simultaneously remain to be determined, because the incidence of Parkinson's disease accompanied by CJD is very low.     

Rapid detection of the prion protein M129V polymorphism with the LightCycler

The common single nucleotide polymorphism at codon 129 of the prion protein gene is a key determinant of the genetic susceptibility to Creutzfeldt-Jakob disease (CJD). Recently, a molecular classification of sporadic CJD based on the M129V genotype in conjunction with other determinants was proposed. In the present study, we describe the development and evaluation of a rapid fluorescent-based assay to detect this polymorphism using the LightCycler system. The two polymorphic alleles could be clearly distinguished by their melting points at 52.1 and 60.4 degrees C, representing the 129V and 129M alleles, respectively. These results were confirmed by DNA sequencing. We evaluated our test in 400 patient samples and found no deviations from the expected melting patterns. The calculated allele frequency for the M-allele was 0.66. Thus, we have established a rapid, reliable fluorescent assay for high-throughput detection of the prion protein M129V polymorphism.     

Creutzfeldt-Jakob disease with a novel four extra-repeat insertional mutation in the PrP gene

OBJECTIVE: To investigate the role of a short insertional mutation in the prion protein (PrP) gene (PRNP) in prion disease pathogenesis. BACKGROUND: The genetic forms of Creutzfeldt-Jakob disease (CJD) are associated with point or insertional mutations in PRNP. Whereas patients with five, six, seven, eight, and nine extra octapeptide repeats show an autosomal dominant pattern of inheritance and features of CJD, Gerstmann-Str?ussler-Scheinker disease, or atypical dementia, patients with one, two, or four extra repeats have typical CJD and lack a family history of neurologic disorder. METHODS: A genetic, neuropathologic, and biochemical study was carried out in a 65-year-old patient with clinical features of sporadic CJD. RESULTS: A novel four extra-repeat insertional mutation of PRNP was found in the patient and in his 59-year-old healthy sister. The patient showed spongiosis, nerve cell loss, and gliosis associated with diffuse PrP immunoreactivity in the cerebral cortex, subcortical gray structures, and cerebellum. A peculiar aspect was the presence of focal PrP deposits in the basal ganglia and hypothalamus, superimposed to diffuse PrP immunoreactivity. The biochemical analysis revealed that both mutant and wild-type PrP participated in the pathologic process, and that the protease-resistant core of the altered PrP isoforms was distinct from that observed in sporadic, acquired, and other genetic forms of CJD. CONCLUSION: These findings support the view that the four extra-repeat insertion in PRNP is a pathogenic mutation with low penetrance rather than a benign polymorphism, and suggest that this mutation results in the formation of a distinct PrP conformer.     

Consensus classification of human prion disease histotypes allows reliable identification of molecular subtypes: an inter-rater study among surveillance centres in Europe and USA

The current classification of human sporadic prion diseases recognizes six major phenotypic subtypes with distinctive clinicopathological features, which largely correlate at the molecular level with the genotype at the polymorphic codon 129 (methionine, M, or valine, V) in the prion protein gene and with the size of the protease-resistant core of the abnormal prion protein, PrP(Sc) (i.e. type 1 migrating at 21?kDa and type 2 at 19?kDa). We previously demonstrated that PrP(Sc) typing by Western blotting is a reliable means of strain typing and disease classification. Limitations of this approach, however, particularly in the interlaboratory setting, are the association of PrP(Sc) types 1 or 2 with more than one clinicopathological phenotype, which precludes definitive case classification if not supported by further analysis, and the difficulty of fully recognizing cases with mixed phenotypic features. In this study, we tested the inter-rater reliability of disease classification based only on histopathological criteria. Slides from 21 cases covering the whole phenotypic spectrum of human sporadic prion diseases, and also including two cases of variant Creutzfeldt-Jakob disease (CJD), were distributed blindly to 13 assessors for classification according to given instructions. The results showed good-to-excellent agreement between assessors in the classification of cases. In particular, there was full agreement (100?%) for the two most common sporadic CJD subtypes and variant CJD, and very high concordance in general for all pure phenotypes and the most common subtype with mixed phenotypic features. The present data fully support the basis for the current classification of sporadic human prion diseases and indicate that, besides molecular PrP(Sc) typing, histopathological analysis permits reliable disease classification with high interlaboratory accuracy.     

Intraneuronal immunoreactivity for the prion protein distinguishes a subset of E200K genetic from sporadic Creutzfeldt-Jakob Disease

Recently, we reported widespread intraneuronal prion protein (PrP) immunoreactivity in genetic Creutzfeldt-Jakob disease (CJD) associated with the E200K mutation. Here, we evaluated 6 cases ofsporadic CJD MM type 1, 5 MV type 2, and 7 VV type 2 and compared their anatomical appearance with that of 29 E200K genetic CJD (gCJD) cases. We also performed double immunolabeling for ubiquitin, p62, early endosomal marker rab5, and immunogold electronmicroscopy in 3 cases. We identified 4 morphological types of intraneuronal PrP immunoreactivity: one type, defined as multiple globular structures, was significantly associated with a subset of E200K gCJD cases and was distinct from the intraneuronal small dotlike PrP immunoreactivity seen in sporadic CJD. Whereas the latter colocalized with rab5, there were single large (7.5 μm-15 μm) globular inclusion body-like structures detected predominantly but not exclusively in E200K gCJD; these were immunoreactive in part for ubiquitin and p62 and showed focal γ-tubulin immunoreactivity, suggesting aggresome features. Ultrastructural examination using immunogold revealed PrP localization in aggresome-like structures and in autophagic vacuoles. These findings suggest that the permanent production of mutant PrP in the E200K gCJD cases overwhelms the ubiquitin-proteasome system and shifts the balance toward selectivemacroautophagy and/or to ubiquitinated inclusion body and aggresome formation as a cytoprotective effort to sequester the mutant protein.     

散发性克-雅病PrP基因129密码子基因型与临床表型14例研究

目的：探讨散发性克－雅病（Creutzfeldt-Jakob disease,CJD)PrP基因129位点密码子基因型与临床表型的关系。方法：对14例散发性CJD患者进行PrP基因129例密码子的检测，并与临床表现进行了分析。结果：（1）根据诊断标准，14例散发性CJD中8例诊断为肯定CJD，6例诊断为很可能CJD。（2）8例诊断肯定CJD组中，PrP基因129例位点密码子为甲硫氨酸纯合型6例，甲充氨酸／缬氨酸2例，6例诊断很可能CJD组的PrP基因129密码子均为甲硫氨酸纯合型。（3）12例PrP基因129位点为甲硫氨酸纯合型的患者以认知障碍起病8例，共济失调1例；视觉障碍2例；肌阵挛1例，病程最长20个月，最短2．5个月，病程中有癫痫5例，肌阵挛6周，视觉障碍6例。7例有典型周期性同步放电（PSD）脑电改变。（4）2例甲硫氨酸／缬氨型患者均以共济失调起病。2个月后才出现痴呆，病理程分析为16个月和20个月，均无典型的PSD。（2）本组散发性CJDPrP基因129位点密码子甲硫氨酸／甲硫氨酸，甲硫氨酸／缬氨酸，分布比例与日本相同，但与西方不同，而且没有缬氨酸纯合型。     

PRNP M129V homozygosity in multiple system atrophy vs. Parkinson’s disease

Multiple system atrophy (MSA) is a neurodegenerative disorder of unknown etiology characterized by extrapyramidal, pyramidal, cerebellar, and autonomic dysfunction in any combination. We report a patient with a 4-year history of MSA who developed dementia associated with sporadic Creutzfeldt–Jakob disease (CJD). Our proband was MM homozygous for the M129V polymorphism within the prion protein gene (PRNP), a known risk factor for CJD. We conducted a case–control study to test the hypothesis that homozygosity for the M129V polymorphism of PRNP occurs more frequently in MSA in comparison to Parkinson’s disease and healthy volunteers. A total of 63 patients with MSA, 54 age-, race- and gendermatched controls with Parkinson’s disease, and 126 matched healthy volunteers were studied. The genotype analysis revealed no significant difference in the codon 129 genotype distribution in MSA as compared to controls. Nonetheless, the frequencies of the MM and VV genotypes were higher in MSA than in Parkinson’s disease. Thus, homozygosity, particularly VV homozygosity, at codon 129 of PRNP is associated with MSA compared to a clinically related but pathophysiologically distinct α-synucleinopathy. Considering the possibility that the prion protein contributes to the pathogenesis of MSA would require confirmation of these findings in an independent patient population.     

Creutzfeldt‐Jakob disease with an M232R substitution: report of a patient showing slowly progressive disease with abundant plaque‐like PrP deposits in the cerebellum

Patients with genetic Creutzfeldt‐Jakob disease in which arginine is substituted for methionine at codon 232 (M232R) of the prion protein gene (CJD232) have been described in Japan, and a recent study has revealed the presence of two clinical phenotypes: a rapidly progressive type (rapid‐type) and a slowly progressive type (slow‐type). Although the former is known to show pathologic features similar to those of classical CJD, the neuropathology of the latter still remains unclear. We report the autopsy findings of slow‐type CJD232 of 37 months' duration in a 73‐year‐old man who had methionine homozygosity at codon 129 of the prion protein gene (129MM). His initial symptoms included agraphia and memory disturbance, followed by relatively slowly progressive dementia. Myoclonus and akinetic mutism became evident 5 and 23 months after disease onset, respectively. The electroencephalogram revealed periodic sharp wave complexes at 7 months before death. The neuropathologic features were partly reminiscent of those of MM2‐cortical‐type sporadic CJD, showing spongiform change of the large confluent vacuole type, neuronal loss with gliosis, and coarse, perivacuolar prion protein deposits, which were later shown to consist of protease‐resistant type 2 prion protein, in the cerebral cortex and striatum. It was of considerable interest that not only was the medial thalamus severely involved, but also that the cerebellar cortex showed loss of Purkinje cells and abundant plaque‐like prion protein deposits. These findings are not a feature of MM2‐cortical‐type sporadic CJD. Whether or not the M232R substitution, in combination with the genetic polymorphism and the molecular type of pathological prion protein, really participates in the development of CJD232 and its different phenotypes awaits further studies.