Prion protein gene codon 129 modulates clinical course of neurological Wilson disease

The polymorphism in the human prion protein gene at codon 129 (PRNP 129) determines susceptibility to prion disease, and has been associated with early onset and a more severe course of other neurodegenerative disorders. Here, we tested the hypothesis that PRNP is a disease-modifying gene in clinical Wilson disease with a neurological phenotype. Allele frequencies in patients with clinical Wilson disease were not different from those of a healthy German control population, and PRNP 129 genotypes did not result in different serum copper, serum ceruloplasmin, or copper in 24-h urine concentrations. PRNP 129 methionine homozygosity, however, led to significantly more severe neurological symptoms in elderly patients, particularly tremor, supporting the notion that PRNP 129 homozygosity contributes to neuronal vulnerability.     

M129V polymorphism in the prion protein gene is not associated with mesial temporal lobe epilepsy in a Han Chinese population

Background and purpose:  Prion protein (PrP) predominantly localized at synapses can modulate neuronal excitability. The prion protein gene ( PRNP ) has been considered one of the candidate genes that play a role in seizure susceptibility. A recent study demonstrated that the 129V allele in the PRNP gene was associated with susceptibility to temporal lobe epilepsy (TLE) in female patients in an Italian population. We screened variations in the open-reading frame (ORF) of the PRNP gene and also replicated the association of the M129V polymorphism with TLE in a Han Chinese population.
Methods:  The M129V polymorphism was genotyped in 320 MTLE patients and 558 non-epilepsy controls. All subjects were Han Chinese.
Results:  No novel polymorphism in the ORF of the PRNP gene was detected. Differences in the genotype distributions and allele frequencies of this polymorphism between cases and controls were insignificant ( P  =   0.24). Further analysis with stratification of the results by gender or age and analysis of clinical features in relation to M129V genotypes also yielded negative findings.
Conclusions:  The present study provides evidence that the M129V polymorphism in the PRNP gene is not associated with MTLE in a Han Chinese population.     

Heidenhain variant in two patients with inherited V210I Creutzfeldt–Jakob disease

Objective: To report two members of the same family carrying the valine to isoleucine point mutation of the prion protein gene (PRNP) and presenting with visual symptoms as initial manifestation as in the “Heidenhain variant” of sporadic Creutzfeldt–Jakob disease (CJD). Methods: Patients underwent neurological examination, electroencephalogram (EEG), brain magnetic resonance images (MRI) and cerebrospinal fluid (CSF) analysis including the Real Time Quaking Induced Conversion (RT-QuIC) test. Disease-specific mutations and polymorphism at codon 129 of the PRNP gene were also studied. Results: Isolated visual symptoms characterized disease onset of both patients followed by progressive neurological signs, dementia and death in 3 (proband) and 9 (his aunt) months. RT-QuIC analysis of CSF samples of both patients revealed the presence of the pathological prion protein and DNA analysis the V210I point mutation of the PRNP and methionine homozygosity at the polymorphic codon 129. Conclusions: This report suggests to consider the diagnosis of V210I genetic CJD in patients presenting with the Heidenhain form of CJD and highlights the importance of genetic testing in all patients with isolated visual manifestations at onset followed by progressive neurological signs and dementia.     

Clinicopathologic characteristics of sporadic Japanese Creutzfeldt–Jakob disease classified according to prion protein gene polymorphism and prion protein type

We analyzed neuropathologic features of 23 Japanese patients with sporadic Creutzfeldt–Jakob disease (sCJD) by means of prion protein (PrP) immunolabeling associated with codon 129 polymorphism of the PrP gene and western blot analysis of protease-resistant PrP (PrP type). Clinical features, particularly age at onset, disease duration, periodic synchronous discharge and presence of myoclonus, were also analyzed. This study included 11 cases of subacute spongiform encephalopathy (SSE), 10 cases of panencephalopathic (PE)-type sCJD and two cases of thalamic-type sCJD, classified according to cerebral pathology findings. According to PrP gene polymorphism and PrP type, 18 cases were classified as MM1-type, two as MV1-type, two as MM2-type and one as MM1 + 2-type sCJD. SSE and PE-type sCJD showed similar clinical features, with the exception of disease duration, codon 129 polymorphism and PrP type. Thalamic-type sCJD showed different clinical features and PrP type. We suggest that SSE and PE-type sCJD comprise the sCJD subtype and that PE-type sCJD is a prolonged pathologic phenotype of SSE. When we compare our results with those from a series of Caucasian sCJD patients, the percentages of codon 129 polymorphisms differed, as did classification based on PrP gene polymorphism and PrP type; our series included many PE-type sCJD cases and disease duration was relatively long and MM2-type cases showed clinicopathologic variability.     

The human prion protein residue 129 polymorphism lies within a cluster of epitopes for T cell recognition

T cell immune responses to central nervous system-derived and other self-antigens are commonly described in both healthy and autoimmune individuals. However, in the case of the human prion protein (PrP), it has been argued that immunologic tolerance is uncommonly robust. Although development of an effective vaccine for prion disease requires breaking of tolerance to PrP, the extent of immune tolerance to PrP and the identity of immunodominant regions of the protein have not previously been determined in humans. We analyzed PrP T cell epitopes both by using a predictive algorithm and by measuring functional immune responses from healthy donors. Interestingly, clusters of epitopes were focused around the area of the polymorphic residue 129, previously identified as an indicator of susceptibility to prion disease, and in the C-terminal region. Moreover, responses were seen to PrP peptide 121-134 containing methionine at position 129, whereas PrP 121-134 [129V] was not immunogenic. The residue 129 polymorphism was also associated with distinct patterns of cytokine response: PrP 128-141 [129M] inducing IL-4 and IL-6 production, which was not seen in response to PrP 128-141 [129V]. Our data suggest that the immunogenic regions of human PrP lie between residue 107 and the C-terminus and that, like with many other central nervous system antigens, healthy individuals carry responses to PrP within the T cell repertoire and yet do not experience deleterious autoimmune reactions.     

Variable phenotype in a P102L Gerstmann-Sträussler-Scheinker Italian family

BACKGROUND: Gerstmann-Str?ussler-Scheinker disease is an autosomal dominant prion disease. The clinical features include ataxia, dementia, spastic paraparesis and extrapyramidal signs. METHODS: We report a new large Italian family affected by Gerstmann-Str?ussler-Scheinker disease. RESULTS: The four generation pedigree includes 11 patients. The mean age at onset +/- SD was 41.4 +/- 16.2 years. Mean disease duration to death in four patients was 5.5 +/- 1.7 years. Two clinical patterns were evident: cognitive impairment with scarce neurological features or ataxia followed by cognitive impairment. Molecular analysis showed P102L mutation in PRNP gene. CONCLUSION: Three Italian families have been reported to date. The variable phenotype has already been reported, and does not appear related to the codon 129 polymorphism.     

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.     

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。     

Neuropathologic variants of sporadic Creutzfeldt-Jakob disease and codon 129 of PrP gene

OBJECTIVES: To determine the contribution of methionine/valine (Met/Val) polymorphism at codon 129 of the prion protein (PrP) gene in the neuropathologic pattern and mechanisms of lesion development in sporadic Creutzfeldt-Jakob disease. BACKGROUND: Creutzfeldt-Jakob disease is a transmissible spongiform encephalopathy characterized by a conformational change of PrP and a variety of PrP deposits in the brain, some of which aggregate into amyloid plaques. METHODS: The authors semiquantitatively assessed neuropathologic lesions and performed PrP immunolabeling in 70 patients (39 Met/Met, 11 Met/Val, 20 Val/Val) who had died in France between 1994 and 1998. RESULTS: Met/Met cases (mild lesions mostly involving the occipital areas, low PrP load, few focal PrP nonamyloid deposits, no amyloid plaques) contrasted with Met/Val cases (marked lesions especially in the parahippocampal gyrus, high PrP load, numerous amyloid plaques) and with Val/Val cases (younger patients, longer course of disease: 11.5 +/- 3 months, and distinct neuropathology: severe lesions heavily involving the hippocampal formation and basal ganglia, high PrP load, numerous focal nonamyloid deposits, rare amyloid plaques). The course of Val/Val patients younger than age 55 was particularly long (19.9 +/- 7 months), and the isocortex bore the brunt of the pathology, suggesting a distinct variety. CONCLUSIONS: Polymorphism at codon 129 modulates the phenotype of sporadic Creutzfeldt-Jakob disease. The Val genotype enhances the production of proteinase-resistant PrP, and the Met/Val genotype facilitates its aggregation into amyloid plaques.     

New variant Creutzfeldt-Jakob disease: three case reports from Leicestershire

Since a report in 1996 of 10 cases of Creutzfeldt-Jakob disease (CJD) with onset in a younger than usual age, a pattern of the disease has emerged. This includes early neuropsychiatric features and sensory symptoms and neurological signs such as ataxia and involuntary movements later in the course of the disease. Three patients with varied clinical presentations and disease course seen at a single neurology unit are described. The first patient was characterised by cognitive and psychiatric symptoms together with neurological signs. The second patient presented with unusual behavioural disturbance and episodes of collapse. The third patient exhibited striking psychomotor retardation and had abnormal CSF and MRI findings. All patients succumbed in a state of akinetic mutism and myoclonus. All three patients had the methionine/methionine genotype at codon 129 of the PrP gene and in two of the three patients a tonsil biopsy was performed with positive results. These two patients also tested positive for the 14.3.3. protein in the CSF. Whereas late features of the disease seem very similar in all cases, the initial presentation was variable and underlines the uncertainty of the range of the clinical phenotype. Successful diagnosis demands a high index of clinical suspicion.     

Clinicopathological characteristics of Creutzfeldt-Jakob disease with a PrP V180I mutation and M129V polymorphism on different alleles]

We report an 80-year-old Japanese man with histologically-diagnosed Creutzfeldt-Jakob disease (CJD). The patient was admitted to our neurological unit because of sudden onset motor aphasia-like symptoms and right hemiparesis. His medical and family histories were unremarkable, and he had taken no medications. Urine, blood counts and blood chemistry were all within normal limits. Cerebrospinal fluid was normal except for elevation of neuron specific enolase (29.9 ng/ml). High-signal intensity was demonstrated in the cortex of the left temporal lobe on T2-weighted MRI images, and the lesion swelled during the initial stage of the disease. There was no enhancement with Gd-DTPA. Serial MRI showed that the high-signal lesion had spread into the bilateral cerebral cortex. The patient developed myoclonus followed by akinetic mutism within 6 months of onset. Consecutive EEGs revealed no periodic synchronous discharge (PSD). He died of pneumonia 21 months after of admission. Autopsy revealed spongiform changes in the cerebral cortex with Kuru plaques, confirming the diagnosis of CJD. The Cerebellar cortex was well preserved. The high-signal lesions corresponded to the spongiform changes in the cerebral cortex. Immunohistochemical analysis showed weak synaptic prion staining. Prion protein (PrP) gene analysis of genomic DNA isolated from the autopsied brain by polymerase chain reaction, the restriction fragment length polymorphisms, and direct sequencing revealed a point mutation (Val-->Ile) at codon 180 and a polymorphism (Met/Val) at codon 129 on different alleles. A few CJD patients with point mutations in codon 180 of the PrP gene have been reported. Combination of the codon 180 point mutation and codon 129 polymorphism may yield an atypical clinicopathological form of CJD that includes late onset, negative PSD, and atypical MRI findings, with preservation of the cerebellar cortex.     

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.     

A novel mutation (G114V) in the prion protein gene in a family with inherited prion disease

Inherited prion diseases are characterized by mutations in the PRNP gene encoding the prion protein (PrP). We report a novel missense mutation in the PRNP gene (resulting in a G114V mutation in PrP) in members of a Uruguayan family with clinical and histopathologic features of prion disease. Affected individuals were characterized by an early age at onset, initial neuropsychiatric symptoms, late dementia with prominent pyramidal and extrapyramidal symptoms, and long disease duration.     

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.     

Clinical and genetic features of human prion diseases in Catalonia: 1993–2002

We describe the clinical and genetic characteristics of the 85 definite or probable human prion diseases cases died between January 1993 and December 2002 in Catalonia (an autonomous community of Spain, 6 million population). Seventy-three (86%) cases were sporadic Creutzfeld-Jakob diseases (sCJD) (49 definite, 24 probable), with a median age at onset of 66 years. The clinical presentation was dementia in 29 cases, ataxia in 14 and visual symptoms in five. The median survival was 3 months. The 14-3-3 assay was positive in 93% cases, 62% presented periodic sharp wave complexes (PSWC) in EEG but only 18% the typical signs on MRI. Forty-eight sCJD were studied for codon 129 PRNP polymorphism: 69% were methionine/methionine (M/M), 14.5% valine/valine (V/V) and 16.5% M/V. Six out of seven V/V cases did not present PSWC and in two survival was longer than 20 months. Eleven cases (13%) were genetic: five familial fatal insomnia and six familial CJD (fCJD). Up to four (67%) fCJD lacked family history of disease, two presented seizures early at onset and one neurosensorial deafness. The only iatrogenic case was related to a dura mater graft. No case of variant CJD was registered. The study confirms in our population the consistent pattern reported worldwide on human prion diseases. Atypical features were seen more frequently in sporadic 129 V/V CJD and fCJD cases.     

Influence of IL-1RN intron 2 variable number of tandem repeats (VNTR) polymorphism on the age at onset of neuropsychiatric symptoms in Wilson's disease

ABSTRACT Wilson's disease (WND) is an autosomal recessive copper storage disease characterized with diverse clinical pictures with the hepatic and/or neuropsychiatric symptoms manifesting at variable age. On the basis of the existing knowledge on possible copper-proinflammatory cytokines interactions, we hypothesized that in WND hereditary, over-/underexpression of PC or anti-inflammatory cytokines may have an impact on the course of the disease. We analyzed the clinical manifestations of WND in relationship to polymorphisms within genes for interleukin-1 receptor antagonist (IL1RN intron 2 VNTR polymorphism), interleukin-1α (IL1A G4845T), IL-1β (IL1B C-511T), IL-6 (IL6 G-174C), and tumor necrosis factor (TNF G-308A) in a total sample of 332 patients. The IL1B C-511T and IL1RN VNTR polymorphisms had an impact on copper metabolism parameters. None of the studied gene polymorphisms had effect on the mode of WND manifestation (neuropsychiatric vs. hepatic). Carriership of the IL1RN *2 allele was related to earlier WND onset, especially among patients with neuropsychiatric form of the disease (median 27.5 vs. 32.0 years, p = .003). Because of the crucial modulatory role of IL1ra on IL-1α and IL-1β proinflammatory functions, IL1ra and its interactions may play a role in the pathogenesis of the neurodegenerative process in WND; our results need to be replicated, possibly in different ethnic groups.     

Elk with a long incubation prion disease phenotype have a unique PrPd profile

The transmissible spongiform encephalopathies (TSEs) invariably result in fatal neurodegeneration and accumulation of PrP, an abnormal form of the host prion protein PrP, encoded by the PRNP gene. A naturally occurring polymorphism (methionine/valine) at PRNP codon 129 is associated with variation in relative disease susceptibility, incubation time, clinical presentation, neuropathology, and/or PrP biochemical characteristics in a range of human TSEs. A methionine/leucine polymorphism at the corresponding site in the Rocky Mountain elk PRNP gene is associated with variation in relative susceptibility and incubation time in the cervid TSE chronic wasting disease. We now report that elk lacking the predisposing 132-methionine allele develop chronic wasting disease after a long incubation period and display a novel PrP folding pattern.     

Clinical course in young patients with sporadic Creutzfeldt-Jakob disease

Sporadic Creutzfeldt-Jakob disease (sCJD) is a rare neurodegenerative disease with the greatest incidence occurring in patients between 60 and 70 years old. Younger patients may also be affected. In this study, we used all case material available from 52 patients with sCJD aged 50 years or younger at disease onset, who were identified between 1993 and 2003 in Germany. The objective of this study was to describe the psychiatric and neurological features of these young patients with emphasis on the different codon 129 genotypes and PrP types, and to compare them with elder patients with sCJD and patients with variant CJD. We also gave particular attention to electroencephalogram, magnetic resonance imaging, and 14-3-3 results, as well as to the neuropathological lesion profile. The clinical syndrome in young patients differs from elder patients with CJD with respect to clinical signs, disease duration, technical investigations, and neuropathological lesion profile. The psychiatric symptoms in young patients with sCJD are similar to the psychiatric symptoms expressed by patients with variant CJD; however, in contrast with the variant cases, young patients with sCJD experience development of prominent dementia early in the disease course.     

A traceback phenomenon can reveal the origin of prion infection

The transmission of prions to animals with incongruent prion protein (PrP) gene (referred to as cross‐sequence transmission) results in a relatively long incubation period and can generate a new prion strain with unique transmissibility designated as a traceback phenomenon. For example, cross‐sequence transmission of bovine spongiform encephalopathy (BSE) prions to human generated variant Creutzfeldt‐Jakob disease (vCJD) prions which retained the transmissibility to mice expressing bovine PrP. This finding suggests that traceback studies could enable us to identify the origin of prions. There are two distinct phenotypes in dura mater graft‐associated Creutzfeldt‐Jakob disease (dCJD), with the majority represented by a non‐plaque‐type of dCJD (np‐dCJD) and the minority by a plaque‐type of dCJD (p‐dCJD). To identify the origin of p‐dCJD, we performed a traceback study using mice expressing human PrP with methionine homozygosity (129M/M) or valine homozygosity (129V/V) at polymorphic codon 129. The characteristics of p‐dCJD such as the accumulation of abnormal isoform of PrP (PrP^Sc) intermediate in size between type 1 and type 2, and plaque‐type PrP deposition in the brain were maintained after transmission to the 129M/M mice. Furthermore, the 129V/V mice were more susceptible to p‐dCJD prions than the 129M/M mice and produced type 2 PrP^Sc that were identical in size to those from the 129V/V mice inoculated with sporadic CJD prions from a patient with 129V/V and type 2 PrP^Sc (sCJD‐VV2). In addition, we performed intracerebral transmission of sCJD‐VV2 prions to the 129M/M mice as an experimental model for p‐dCJD. These 129M/M mice showed the accumulation of the intermediate type PrP^Sc and plaque‐type PrP deposition in the brain. These results suggest that p‐dCJD could be caused by cross‐sequence transmission of sCJD‐VV2 prions to individuals with the 129M/M genotype.     

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.