Association of the PRNP regulatory region polymorphisms with the occurrence of sporadic Creutzfeldt-Jakob disease

The prion protein (PrP) plays a central role in the pathogenesis of Creutzfeldt-Jakob disease and other transmissible spongiform encephalopathies (TSEs). Mutations in the coding region of the prion protein (PRNP) gene are linked to inherited forms of TSEs whereas aetiology of sporadic CJD (sCJD) remains obscure. It remains unclear whether the primary DNA sequence at non-coding region of PRNP gene influences development of the sCJD. Several recent reports showed non-coding region polymorphisms associated with sCJD but other could not support those findings. To test the hypothesis that there is a relationship between SNPs polymorphisms of PRNP non-coding regions and susceptibility to sCJD, we compared the primary structure of the regulatory region of the PRNP in 45 Dutch sCJD patients and in 135 healthy controls. We found a significant linkage of +310 C allele (OR 0.27, 95% CI 0.09-0.77; P = 0.009) and +310G/C genotype (OR 0.33, 95% CI 0.11-0.98; P = 0.048) with sCJD. No differences in frequencies of genotypes and allele of -101C/G and +258 G/A polymorphisms were found between sCJD patients and controls. We found two haplotypes protecting from sCJD (C-V in block 1 and G-C in block 2) and one susceptible haplotype for sCJD (G-G in block 2). Our findings support the hypothesis that polymorphism in the regulatory region of the PRNP gene may play an important role in the pathogenesis of sCJD.     

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.     

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.     

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.     

Classification of sporadic Creutzfeldt-Jakob disease based on molecular and phenotypic analysis of 300 subjects.

Phenotypic heterogeneity in sporadic Creutzfeldt-Jakob disease (sCJD) is well documented, but there is not yet a systematic classification of the disease variants. In a previous study, we showed that the polymorphic codon 129 of the prion protein gene (PRNP), and two types of protease-resistant prion protein (PrP(Sc)) with distinct physicochemical properties, are major determinants of these variants. To define the full spectrum of variants, we have examined a series of 300 sCJD patients. Clinical features, PRNP genotype, and PrP(Sc) properties were determined in all subjects. In 187, we also studied neuropathological features and immunohistochemical pattern of PrP(Sc) deposition. Seventy percent of subjects showed the classic CJD phenotype, PrP(Sc) type 1, and at least one methionine allele at codon 129; 25% of cases displayed the ataxic and kuru-plaque variants, associated to PrP(Sc) type 2, and valine homozygosity or heterozygosity at codon 129, respectively. Two additional variants, which included a thalamic form of CJD and a phenotype characterized by prominent dementia and cortical pathology, were linked to PrP(Sc) type 2 and methionine homozygosity. Finally, a rare phenotype characterized by progressive dementia was linked to PrP(Sc) type 1 and valine homozygosity. The present data demonstrate the existence of six phenotypic variants of sCJD. The physicochemical properties of PrP(Sc) in conjunction with the PRNP codon 129 genotype largely determine this phenotypic variability, and allow a molecular classification of the disease variants.     

A subtype of sporadic prion disease mimicking fatal familial insomnia.

OBJECTIVE: To establish a variant of sporadic prion disease as the sporadic form of fatal familial insomnia (FFI). BACKGROUND: FFI is a recently described prion disease characterized clinically by severe sleep impairment, dysautonomia, and motor signs, and pathologically by atrophy of thalamic nuclei, especially the medial dorsal and anterior ventral, and of the inferior olive. FFI is linked to the D178N mutation coupled with the methionine codon at position 129 in the prion protein gene (PRNP). It is also identified by the properties of the abnormal prion protein (PrP(Sc)), which has the relative molecular mass of 19 kDa, corresponding to the so-called type 2, and a marked underrepresentation of the unglycosylated form relative to the diglycosylated and monoglycosylated forms. METHODS: Clinical, pathologic, PrP(Sc), and PRNP data from 5 subjects with a sporadic prion disease phenotypically similar to FFI were collected and analyzed. RESULTS: All 5 subjects had a disease clinically similar and histopathologically virtually identical to FFI. PrP(Sc) type 2 was present in all subjects in amount and distribution similar to those of FFI. However, the PrP(Sc) did not show the striking underrepresentation of the unglycosylated isoform of the protein that is characteristic of FFI. Moreover, none of the subjects had the D178N PRNP mutation but all were homozygous for methionine at codon 129. CONCLUSION: This condition is likely to represent the sporadic form of FFI and the term "sporadic fatal insomnia" is proposed.     

Reconstructing prions: fibril assembly from simple yeast to complex mammals

With the epizootics of bovine spongiform encephalopathy (BSE) in North American cattle, BSE infections in goats, new forms of human Creutzfeldt-Jakob disease (CJD) and the spread of chronic wasting disease in North American deer and elk, one wonders whether we are gaining control over the transmissible spongiform encephalopathies (TSEs). Although many basic scientific questions in the prion field remain hotly debated and unresolved [1], including the function of the cellular prion protein (PrP), light has been shed on a diverse array of topics, and discussions at the latest TSE meeting ranged broadly from yeast prion fibril assembly to mammalian prion neurotoxicity to future TSE therapies. Prion diseases are protein misfolding disorders which cause degeneration of the central nervous system (CNS) and ultimately death. The unique and surprising feature is that prion diseases are infectious. Yeast prions are derived from proteins differing from the mammalian PrP but are also infectious, self propagating proteins which typically can convert into an aggregated, amyloidogenic form having high beta sheet content. The simple yeast organism has served as a valuable model for understanding aspects of prion biology, such as prion fibril assembly.     

Prion protein glycotype analysis in familial and sporadic Creutzfeldt-Jakob disease patients

Creutzfeldt-Jakob disease (CJD) and other transmissible spongiform encephalopathies (TSEs) are characterised by the accumulation of a pathological conformer of PrP, named PrPsc. Molecular weight and glycosylation of the protease-resistant core of PrPsc (PrP27-30) are heterogeneous in different forms of TSEs. We analysed PrP27-30 glycotypes in a large number of TSE-affected patients: 50 sporadic CJD (sCJD), 1 iatrogenic CJD, 1 Gerstmann-Str?ussler-Scheinker syndrome (GSS) with the Pro102Leu mutation of PrP, 3 familial CJD (fCJD) with the Glu200Lys mutation and, for the first time, 7 fCJD with the Val210ll3e mutation. All patients were screened for the polymorphic codon 129 of the PrP gene. PrP27-30 deglycosylation and PrPsc immunohistochemistry were performed in selected cases. We found that two PrP27-30 glycotypes (type 1A and type 2A) are produced in sCJD. Type 1A is more frequently associated with methionine than valine in position 129. Type 1A is also formed in Val210lle fCJD. In Glu200Lys fCJD and GSS patients, we found that PrP27-30 has the same mobility of type 1 but different glycosylation ratios (type 1B). Our findings indicate that the polymorphic residue 129 of PrP has a leading role in determining the proteinase degradation site of PrPsc while mutant residues 102 or 200 influence only the glycosylation pattern.     

Type 1 protease resistant prion protein and valine homozygosity at codon 129 of PRNP identify a subtype of sporadic Creutzfeldt-Jakob disease

A man was studied with sporadic Creutzfeldt-Jakob disease (sCJD) who had serial cortical syndromes evolving over 15 months without significant ataxia, prominent myoclonus, or periodic complexes on EEG examinations. This clinical phenotype correlated with a predominantly cortical and striatal distribution of lesions and accumulation of protease resistant prion protein with relative sparing of the brainstem or cerebellum. No amyloid plaques were seen and prion protein (PrP) immunohistochemistry only demonstrated very faint granular deposits in the cerebral cortex. Molecular analysis showed homozygosity for valine at codon 129 in the prion protein gene (PRNP) and protease resistant prion protein type 1 deposition. The comparison of molecular and clinicopathological features of the present case with those previously reported in sCJD, indicates that valine homozygosity at codon 129 and type 1 protease resistant prion protein are associated with a distinct phenotypic variant of sCJD. The data also support the view that the PRNP codon 129 polymorphism and the physicochemical properties of the protease resistant prion protein are major determinants of phenotypic variability in sCJD.     

M129V variation in the prion protein gene and psychotic disorders: relationship to neuropsychological and psychopathological measures

The methionine/valine polymorphism at position 129 in the prion protein gene, PRNP M129V, is a known risk factor for Creutzfeldt-Jakob disease (CJD). Psychiatric manifestations including psychosis are common in the early phase of CJD and it has therefore been hypothesized that the prion protein could be involved in psychotic disorders. Moreover, among the various hypothesized functions of the prion protein, a role in synaptic activity has been described. We have studied the PRNP M129V variant with regard to psychotic disorders from two perspectives: first as a genetic risk factor and second as a genetic factor influencing phenotypic variation. A case-control study of 482 psychotic patients and 502 controls indicated that differences between patients and controls were not present in genotype distributions or allele frequencies. We also studied the influence of this variant in psychopathological symptomatology and neuropsychological performance in a subgroup of 159 psychotic patients. In our sample, patients homozygous for valine at this position presented less severe scores in the general psychopathological subscale (p=0.003) and in the sum of the total items (p=0.007) of the Positive and Negative Syndrome Scale (PANSS). Also, homozygote VV patients presented better scores in most neuropsychological tests, the most significant result of which was for delayed visual memory (p=0.021). In summary, our results do not support the hypothesis that M129V is a susceptibility factor for psychotic disorders. However, it could influence their phenotypic variation at the psychopathological and neuropsychological level. Independent replications are needed to confirm that being homozygotic for valine at PRNP M129V position is associated with better psychopathological and neuropsychological scores in psychotic disorders.     

Creutzfeldt-Jakob disease, prion protein gene codon 129VV, and a novel PrPSc type in a young British woman

BACKGROUND: Variant Creutzfeldt-Jakob disease (vCJD) is an acquired prion disease causally related to bovine spongiform encephalopathy that has occurred predominantly in young adults. All clinical cases studied have been methionine homozygotes at codon 129 of the prion protein gene (PRNP) with distinctive neuropathological findings and molecular strain type (PrP(Sc) type 4). Modeling studies in transgenic mice suggest that other PRNP genotypes will also be susceptible to infection with bovine spongiform encephalopathy prions but may develop distinctive phenotypes. OBJECTIVE: To describe the histopathologic and molecular investigation in a young British woman with atypical sporadic CJD and valine homozygosity at PRNP codon 129. DESIGN: Case report, autopsy, and molecular analysis. SETTING: Specialist neurology referral center, together with the laboratory services of the MRC [Medical Research Council] Prion Unit. Subject Single hospitalized patient. MAIN OUTCOME MEASURES: Autopsy findings and molecular investigation results. RESULTS: Autopsy findings were atypical of sporadic CJD, with marked gray and white matter degeneration and widespread prion protein (PrP) deposition. Lymphoreticular tissue was not available for analysis. Molecular analysis of PrP(Sc) (the scrapie isoform of PrP) from cerebellar tissue demonstrated a novel PrP(Sc) type similar to that seen in vCJD (PrP(Sc) type 4). However, this could be distinguished from the typical vCJD pattern by an altered protease cleavage site in the presence of the metal ion chelator EDTA. CONCLUSIONS: Further studies will be required to characterize the prion strain seen in this patient and to investigate its etiologic relationship with bovine spongiform encephalopathy. This case illustrates the importance of molecular analysis of prion disease, including the use of EDTA to investigate the metal dependence of protease cleavage patterns of PrP(Sc).     

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 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.     

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

The authors investigated two unrelated patients with Creutzfeldt-Jakob disease (CJD) with clinical features of sporadic CJD (sCJD) carrying one extra octapeptide repeat in the prion protein (PrP) gene (PRNP). A synaptic type PrP distribution throughout the cerebral gray matter and plaque-like PrP deposits in the subcortical gray structures were detected immunocytochemically. The different patterns of PrP deposition were associated with distinct types of protease-resistant PrP, similar to type 1 and type 2 of sCJD. The features suggest that this insertion is a pathogenic mutation.     

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.     

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.     

Codon 129 polymorphism of prion protein gene in sporadic Alzheimer's disease

Codon 129 polymorphism of the prion protein gene represents a major genetic risk factor for Creutzfeldt-Jakob disease (CJD). Both CJD and Alzheimer's disease (AD) are brain amyloidoses and it would be possible that codon 129 polymorphism plays a role in the susceptibility to AD. In order to investigate this polymorphism in AD the distribution of polymorphic codon 129 of the PRNP gene in 194 probable AD and 124 controls selected in Italy and 109 neuropathologically verified AD and 58 matched controls recruited in the USA was studied. No significant association was found for the PRNP polymorphism in AD compared to controls either in Probable or in Definite AD series even after stratification for APOE polymorphism. This study does not support a role of PRNP polymorphism as a susceptibility factor for AD.     

PRNP 1368 polymorphism is not associated with sporadic Creutzfeldt-Jakob disease in the Korean population

Background:  Human prion protein gene ( PRNP ) is considered a critical and fundamental gene in determining the incidence of human prion diseases. Codons 129 and 219 play an important role in the susceptibility to sporadic Creutzfeldt-Jakob disease (CJD). An association between sporadic CJD and the polymorphism ( PRNP 1368) in an upstream of PRNP exon 1 has been reported in the British and German populations, but study in the Dutch population has failed to confirm an association.
Purpose:  To investigate whether the PRNP 1368 polymorphism is associated with sporadic CJD in the Korean population.
Methods:  We compared the genotype and allele frequencies of PRNP 1368 polymorphism in 171 sporadic CJD patients with those in 212 healthy Koreans.
Result and conclusion:  A significant difference of genotype and allele frequencies at PRNP 1368 was found between the normal Korean population and various European populations. In contrast to the results in the British and German populations, our study does not show a significant difference in genotype ( P =  0.2763) and allele ( P  =   0.3750) frequencies of PRNP 1368 between sporadic CJD and normal controls.     

Prion protein codon 129 genotype prevalence is altered in primary progressive aphasia

The prion protein (PrP) is central to the prion diseases, although a role in other neurodegenerative diseases has been postulated. A common polymorphism (Met or Val) at codon 129 of the PrP gene (PRNP) features prominently in the risk and phenotype, of prion disease, and an abnormality in its distribution frequency may signal a role for PrP in other diseases. We conducted a case-control study to compare the PRNP codon 129 genotype distribution in Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), and primary progressive aphasia (PPA), including 281 AD, 256 ALS, 39 PPA, and 415 healthy control subjects. Statistical analysis was applied to determine the presence or absence of disease-specific genotype associations. The distribution of codon 129 genotypes was similar among healthy control, AD, and ALS subjects, although the heterozygous state was significantly overrepresented (age-adjusted odds ratio, 8.47) in PPA, a rare condition of unknown cause. Although these findings do not entirely exclude a role for PrP in AD or ALS, they do not support the codon 129 genotype as a risk factor for either disease. However, the strong association between heterozygosity and PPA raises new questions about its cause and the role of PrP in other neurodegenerative diseases.     

Genotyping of the prion protein gene at codon 129

Sporadic, iatrogenic and new variant forms of Creutzfeldt-Jakob disease are associated with a predisposition for disease depending on a homozygosity at amino acid residue 129 of the prion protein gene (PRNP). A novel polymerase chain reaction/restriction digestion assay to screen for this polymorphism was developed and proved after comparison with a previously used method to be advantageous. Furthermore, for prevention of incorrect results an internal control for the restriction digestion was constructed. The feasibility of this method was tested in a cohort of 300 healthy Caucasian subjects. Of this normal population, 48.7% were heterozygous at codon 129, 43% homozygous for methionine and 8.3% for valine. Received: 22 July 1998 / Revised, accepted: 25 September 1998