Thursday, November 19, 2009

Inherited Creutzfeldt–Jakob disease in a Dutch patient with a novel five octapeptide repeat insertion and unusual cerebellar morphology

J Neurol Neurosurg Psychiatry 2009;80:1386-1389 doi:10.1136/jnnp.2008.169359

Short report

Inherited Creutzfeldt–Jakob disease in a Dutch patient with a novel five octapeptide repeat insertion and unusual cerebellar morphology

C Jansen1, J C van Swieten2, S Capellari3, R Strammiello3, P Parchi3, A J M Rozemuller1 + Author Affiliations

1Dutch Surveillance Centre for Prion Diseases, University Medical Centre Utrecht, Utrecht, The Netherlands 2Department of Neurology, Erasmus University Medical Centre, Rotterdam, The Netherlands 3Dipartimento di Scienze Neurologiche, Università di Bologna, Bologna, Italy Correspondence to Dr C Jansen, Dutch Surveillance Centre for Prion Diseases, University Medical Centre Utrecht, Heidelberglaan 100, PO Box 85500, 3508 GA, Utrecht, The Netherlands; Received 2 December 2008 Revised 22 February 2009 Accepted 5 March 2009 Abstract An atypical case of inherited Creutzfeldt–Jakob disease (CJD) is described in a 35-year-old Dutch woman, homozygous for methionine at codon 129 of the prion protein gene (PRNP). The clinical phenotype was characterised by slowly progressive cognitive decline and parkinsonism. Neuropathological findings consisted of scanty spongiosis and only faint to absent immunohistochemical staining for the abnormal prion protein, PrPSc, with patchy deposits in the cerebellar cortex. Purkinje cells were abnormally located in the molecular layer of the cerebellum. Western blot analysis showed the co-occurrence of PrPSc types 1 and 2 with an unusual distribution. Sequence analysis disclosed a novel 120 bp insertion in the octapeptide repeat region of the PRNP, encoding five additional R2 octapeptide repeats. These features define an unusual neuropathological phenotype and novel genotype, further expanding the spectrum of genotype–phenotype correlations in inherited prion diseases and emphasising the need to carry out pre-mortem PRNP sequencing in all young patients with atypical dementias.


METHODS Case history The patient presented with forgetfulness and difficulties in writing at the age of 35 years, after the birth of her second child. Her family noted that she had become increasingly absentminded and apathetic. Her clinical history was otherwise unremarkable. Her father had suffered from dementia and parkinsonism from the age of 45 years and died at the age of 55 years. At neurological examination, 2.5 years after the first symptoms, the patient was disoriented in time and place, and exhibited echolalia, perseveration and disturbed visual perception. She had a masked face with vertical gaze palsy, and increased tone of the extremities. Neuropsychological evaluation revealed an intact memory with acalculia, agraphia and apraxia. Brain MRI showed generalised cortical atrophy without evidence of hyperintensity or atrophy of either the caudate nucleus or the basal ganglia (fig 1A). The 14-3-3 test in CSF was negative. An electroencephalogram was not recorded. Genetic analysis revealed no abnormalities in the tau protein gene (MAPT), the Presenilin 1 gene (PSEN1) or the Huntingtin gene. Over the next 3 years, rigidity increased with the appearance of a slight tremor in her right hand, without any beneficial effect on levodopa and amantadin treatment. She increasingly developed dysarthria and swallowing problems, and suffered from anxiety and panic attacks. She was admitted to a nursing home where she died from bronchopneumonia at the age of 42 years, 92 months after the clinical onset of the disease.



Seventeen patients with six different 5-OPRI have been described so far in the literature.6 As in other inherited prion diseases, these disorders show a considerable degree of phenotypic variability, partly accounted for by the codon 129 Met/Val polymorphism. Age at onset in codon 129 heterozygous patients is usually later (58.0 years) than in codon 129 homozygous patients (42.3 years).6 Approximately half of these patients show a disease duration of more than 60 months. Although the clinical and pathological features of 5-OPRI mutations are relatively well known, genotype–phenotype correlation has not been clearly established, warranting the description of further genetic cases.

In this report, we describe a novel insertion mutation in PRNP, consisting of five extra R2 octapeptide repeats (R1-(R2)7- R3-R4). The clinical phenotype in our patient was characterised by slowly progressive cognitive decline, parkinsonism, anxiety and a long disease duration of 92 months. Neuropathological findings included scanty spongiosis and faint synaptic or even absent immunohistochemical staining, except for small patchy deposits in the cerebellar cortex, without the characteristic perpendicular orientation to the meningeal outline, as described in other patients with insertion mutations.8 12 An intriguing finding, although described before in three other patients with a 5-OPRI mutation,13 was the abnormal localisation of Purkinje cells in the molecular layer of the cerebellum. The type of abnormalities, combined with the absence of ataxia and significant cerebellar pathology, strongly suggest this defect as being longstanding and likely related to a developmental defect. Thus although largely speculative, the observation may suggest a role for PrPC in cerebellar neuronal migration or in the elimination of misplaced Purkinje cells during development which likely involve the programmed cell death machinery, as recently suggested.14 Furthermore, in the absence of a specific histopathological picture, the observation of misplacement of Purkinje cells in the molecular layer might be a helpful diagnostic clue prompting the suspicion of inherited prion disease with OPRI mutation.

Another interesting finding was the co-occurrence of PrPSc types 1 and 2 in brain homogenates, as demonstrated by immunoblotting. To our knowledge, this has only been described once before in a patient with one extra octapeptide repeat in PRNP, who showed widespread spongiosis and diffuse synaptic immunoreactivity in all cortical lobes.15 In light of the scanty spongiosis and faint immunohistochemical staining in the brain of our patient, the presence of type 2 protein is a peculiar finding, since in methionine homozygotes (MM) at codon 129, type 2 is usually associated with prominent spongiosis with confluent vacuoles and more consistent coarse and perivacuolar deposits of PrPSc in the cerebral cortex.11 Furthermore, type 2 in MM cases preferentially accumulates in the cerebral cortex11 whereas it was mainly detected in the striatum and cerebellum in the present case. The 5-OPRI mutation in this patient was probably inherited in an autosomal dominant pattern but a positive family history in patients with inherited prion disease is not obligate. In all patients with a clinical history of frontotemporal dementia or atypical dementia and abnormal localisation of Purkinje cells in the molecular layer of the cerebellum, inherited prion disease should always be considered and pre-mortem PRNP sequencing should be carried out.

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Wednesday, August 12, 2009

Neurobiology of Disease A New Transgenic Mouse Model of GSS Syndrome Caused by the A117V Mutation of PRNP

Neurobiology of Disease A New Transgenic Mouse Model of Gerstmann–Sträussler–Scheinker Syndrome Caused by the A117V Mutation of PRNP

Wenbin Yang,1 Julie Cook,1 Benjamin Rassbach,1 Azucena Lemus,2 Stephen J. DeArmond,2 and James A. Mastrianni1

1Department of Neurology, University of Chicago, Chicago, Illinois 60637, and 2Department of Neuropathology, University of California, San Francisco, San Francisco, California 94143

Correspondence should be addressed to James A. Mastrianni, Department of Neurology, University of Chicago, MC2030, 5841 South Maryland Avenue, Chicago, IL 60637. Email: mhtml:%7B33B38F65-8D2E-434D-8F9B-8BDCD77D3066%7Dmid://00000475/!

Gerstmann–Sträussler–Scheinker syndrome (GSS) is a genetic prion disease typified clinically by the development of progressive ataxia and dementia, and histopathologically by the presence of prion protein (PrP) amyloid plaques in the CNS, especially within the cerebellum. Several mutations of the PrP gene (PRNP) are associated with GSS, but only the P102L mutation has been convincingly modeled in transgenic (Tg) mice. To determine whether other mutations carry specific GSS phenotypic information, we constructed Tg mice that express PrP carrying the mouse homolog of the GSS-associated A117V mutation. Tg(A116V) mice express approximately six times the endogenous levels of PrP, develop progressive ataxia by 140 d, and die by 170 d. Compared with a mouse model of transmissible Creutzfeldt–Jakob disease (CJD), the ataxia of Tg(A116V) mice is more prominent, and the course of disease is more protracted, paralleling that observed in human disease. Neuropathology includes mild scattered vacuolation and prominent, mainly cerebellar localized, thioflavin S-positive PrP plaques comprised of full-length PrPA116V. In some mice, more prominent vacuolation or a noncerebellar distribution of PrP plaques was evident, suggesting some variability in phenotype. The biophysical properties of PrP from Tg(A116V) mice and human GSS(A117V) revealed a similarly low fraction of insoluble PrP and a weakly protease-resistant 13 kDa midspan PrP fragment, not observed in CJD. Overall, Tg(A116V) mice recapitulate many clinicopathologic features of GSS(A117V) that are distinct from CJD, supporting PrPA116V to carry specific phenotypic information. The occasional variation in histopathology they exhibit may shed light on a similar observation in human GSS(A117V).

-------------------------------------------------------------------------------- Received June 2, 2009; revised June 30, 2009; accepted July 3, 2009.

Correspondence should be addressed to James A. Mastrianni, Department of Neurology, University of Chicago, MC2030, 5841 South Maryland Avenue, Chicago, IL 60637. Email: mhtml:%7B33B38F65-8D2E-434D-8F9B-8BDCD77D3066%7Dmid://00000475/!

Thursday, May 28, 2009

Cerebrospinal fluid biomarkers in human genetic transmissible spongiform encephalopathies

J Neurol DOI 10.1007/s00415-009-5163-x

Cerebrospinal fluid biomarkers in human genetic transmissible spongiform encephalopathies

Anna Ladogana Æ Pascual Sanchez-Juan Æ Eva Mitrova´ Æ Alison Green Æ Natividad Cuadrado-Corrales Æ Raquel Sa´nchez-Valle Æ Silvia Koscova Æ Adriano Aguzzi Æ Theodoros Sklaviadis Æ Jerzy Kulczycki Æ Joanna Gawinecka Æ Albert Saiz Æ Miguel Calero Æ Cornelia M. van Duijn Æ Maurizio Pocchiari Æ Richard Knight Æ Inga Zerr

Received: 16 December 2008 / Revised: 8 April 2009 / Accepted: 27 April 2009  Springer-Verlag 2009

Abstract The 14-3-3 protein test has been shown to support the clinical diagnosis of sporadic Creutzfeldt-Jakob disease (CJD) when associated with an adequate clinical context, and a high differential potential for the diagnosis of sporadic CJD has been attributed to other cerebrospinal fluid (CSF) proteins such as tau protein, S100b and neuron specific enolase (NSE). So far there has been only limited information available about biochemical markers in genetic transmissible spongiform encephalopathies (gTSE), although they represent 10–15% of human TSEs. In this study, we analyzed CSF of 174 patients with gTSEs for 14-3-3 (n = 166), tau protein (n = 78), S100b (n = 46) and NSE (n = 50). Levels of brain-derived proteins in CSF varied in different forms of gTSE. Biomarkers were found positive in the majority of gCJD (81%) and insert gTSE (69%), while they were negative in most cases of fatal familial insomnia (13%) and Gerstmann-Stra¨ussler- Scheinker syndrome (10%). Disease duration and codon 129 genotype influence the findings in a different way than in sporadic CJD.



Data on brain-derived proteins in the CSF of patients with genetic TSE are limited and conflicting results have been reported, mostly because they are frequently based on single case observations (see Table 4). In these reports, sensitivity of biochemical markers in CSF is reported to be lower than in sporadic CJD and this was explained in terms of prolonged disease duration and relatively slow disease progression. Because of the limited numbers of patients, no detailed analysis on this topic is available.

In this study we provide data on four brain-derived proteins in a cohort of patients with various forms of genetic TSE. We found firm evidence for elevated concentrations of 14-3-3, tau, S100b and NSE in the CSF of patients with genetic CJD, but not in FFI or GSS patients. Of interest, the median concentrations for tau, S100b and NSE were similar to those detected in sporadic CJD in other studies [1, 16, 20]. In our previous study on sporadic CJD, we reported median tau levels in the range of

6,000 pg/ml, which is not significantly different from what we found in gCJD patients [21]. These results are concordant with the observation that some gCJD might present clinical similarities with sporadic CJD [11, 15]. Indeed, these cases are often misclassified as sporadic CJD if family history and genetic testing are not done.

The rate of elevated levels of 14-3-3, tau, NSE and S100b in genetic CJD was comparable to that observed in sporadic CJD [3, 20, 26, 27]. In other forms of gTSE, such as FFI and GSS, these tests were consistently negative. Although levels of tau in FFI and GSS patients were lower than the cut-off levels given for CJD, they were still elevated if compared to non-demented controls [24].

The crude analyses of disease modifying factors of the 14-3-3 test in gCJD revealed that age at onset and PRNP codon 129 genotype influenced sensitivity. 14-3-3 test sensitivity was lower in patients with disease onset before 40 years. These data parallel the results performed on sporadic CJD [20]. However, while in the multivariate analysis age remained as an independent variable in sporadic CJD, in gCJD it did not. Interestingly, in gCJD the PRNP codon 129 genotype influences 14-3-3 sensitivity in a different way with respect to what has been observed in sporadic CJD. Valine homozygous gCJD patients had a lower sensitivity in the 14-3-3 test than heterozygous patients. Though there are too few patients to draw any definite conclusions, a possible explanation might be that the PRNP mutations coupled with the valine alleles (R208H, D178N, E196K) confer low sensitivity to 14-3-3.

The biological significance of brain-derived proteins in the CSF of patients with TSEs remains to be determined. It is generally assumed that the release of 14-3-3, tau and

NSE proteins in the CSF is a consequence of leakage into the CSF following rapid neuronal damage. Recently, a systematic analysis of brain-derived proteins in CSF and neuropathological lesions has shown that the levels of these proteins are the consequence of both the degree of neuronal damage and the localization of the most affected areas [2]. For example NSE levels correlated with damage of subcortical areas (such as the thalamus) and tau protein levels correlated with the degree of spongiform changes in the frontal cortex. Our findings on inverse correlation of tau levels and the number of octapeptide repeats are of interest, since the number of repeats has been correlated to the type of cerebellar PrPSc deposits [28].

In conclusion, the validity of the biomarkers varied among the different forms of gTSEs. Sensitivity of biomarkers was high in those forms, which are clinically more similar to sporadic CJD, such as genetic CJD and insert gTSEs.

Keywords Creutzfeldt-Jakob disease  CSF proteins  14-3-3 protein  Tau

A. Ladogana  M. Pocchiari Department of Cellular Biology and Neurosciences, Instituto Superiore di Sanita, Viale Regina Elena 299, 00161 Rome, Italy e-mail: mhtml:%7B33B38F65-8D2E-434D-8F9B-8BDCD77D3066%7Dmid://00000094/!

M. Pocchiari e-mail: mhtml:%7B33B38F65-8D2E-434D-8F9B-8BDCD77D3066%7Dmid://00000094/!

P. Sanchez-Juan Centro de Investigacion Biomedica en Red sobre Enferemedades neurodegenerativas (CIBERNED) and Institute for Formation and Research of the Fundacion ‘‘Marques de Valdecilla’’ (IFIMAV), Santander, Spain e-mail: mhtml:%7B33B38F65-8D2E-434D-8F9B-8BDCD77D3066%7Dmid://00000094/!

E. Mitrova´  S. Koscova National Reference Centre for Prion Diseases, Research Base of Slovak Medical University, Limbova´ 14, 833-03 Bratislava, Slovakia e-mail: mhtml:%7B33B38F65-8D2E-434D-8F9B-8BDCD77D3066%7Dmid://00000094/!

S. Koscova e-mail: mhtml:%7B33B38F65-8D2E-434D-8F9B-8BDCD77D3066%7Dmid://00000094/!

A. Green  R. Knight National CJD Surveillance Unit, The University of Edinburgh, EH4-2XU Edinburgh, UK e-mail: mhtml:%7B33B38F65-8D2E-434D-8F9B-8BDCD77D3066%7Dmid://00000094/!

N. Cuadrado-Corrales  M. Calero Instituto de Salud Carlos III, Centro Nacional de Microbiologia, Ctra. Majadahonda, 28220 Madrid, Spain e-mail: mhtml:%7B33B38F65-8D2E-434D-8F9B-8BDCD77D3066%7Dmid://00000094/!

M. Calero e-mail: mhtml:%7B33B38F65-8D2E-434D-8F9B-8BDCD77D3066%7Dmid://00000094/!

R. Sa´nchez-Valle  A. Saiz Department of Neurology, Hospital Clinic Provincial de Barcelona, Villarroel 170, 08036 Barcelona, Spain e-mail: mhtml:%7B33B38F65-8D2E-434D-8F9B-8BDCD77D3066%7Dmid://00000094/!

A. Saiz e-mail: mhtml:%7B33B38F65-8D2E-434D-8F9B-8BDCD77D3066%7Dmid://00000094/!

A. Aguzzi National Reference Center for Human Prion Diseases (NRPE), Institute of Neuropathology, Schmelzbergstr.12, 8091 Zurich, Switzerland e-mail: mhtml:%7B33B38F65-8D2E-434D-8F9B-8BDCD77D3066%7Dmid://00000094/!

T. Sklaviadis Laboratory of Pharmacology, Department of Pharmaceutical Sciences, School of Health Sciences, Aristotle University of Thessaloniki, 54124 Thessaloni´ki, Greece e-mail: mhtml:%7B33B38F65-8D2E-434D-8F9B-8BDCD77D3066%7Dmid://00000094/!

J. Kulczycki I-st Neurological Department, Institute of Psychiatry and Neurology, Sobieskiego 9, 02-957 Warsaw, Poland e-mail: mhtml:%7B33B38F65-8D2E-434D-8F9B-8BDCD77D3066%7Dmid://00000094/!

Sunday, May 10, 2009

Meeting of the Transmissible Spongiform Encephalopathies Committee On June 12, 2009 (Singeltary submission)