| 1. |
- Smith, Bradley N., et al.
(författare)
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The C9ORF72 expansion mutation is a common cause of ALS+/-FTD in Europe and has a single founder
- 2013
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Ingår i: European Journal of Human Genetics. - London : Nature Publishing Group. - 1018-4813 .- 1476-5438. ; 21:1, s. 102-108
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Tidskriftsartikel (refereegranskat)abstract
- A massive hexanucleotide repeat expansion mutation (HREM) in C9ORF72 has recently been linked to amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Here we describe the frequency, origin and stability of this mutation in ALS+/-FTD from five European cohorts (total n = 1347). Single-nucleotide polymorphisms defining the risk haplotype in linked kindreds were genotyped in cases (n = 434) and controls (n = 856). Haplotypes were analysed using PLINK and aged using DMLE+. In a London clinic cohort, the HREM was the most common mutation in familial ALS+/-FTD: C9ORF72 29/112 (26%), SOD1 27/112 (24%), TARDBP 1/112 (1%) and FUS 4/112 (4%) and detected in 13/216 (6%) of unselected sporadic ALS cases but was rare in controls (3/856, 0.3%). HREM prevalence was high for familial ALS+/-FTD throughout Europe: Belgium 19/22 (86%), Sweden 30/41 (73%), the Netherlands 10/27 (37%) and Italy 4/20 (20%). The HREM did not affect the age at onset or survival of ALS patients. Haplotype analysis identified a common founder in all 137 HREM carriers that arose around 6300 years ago. The haplotype from which the HREM arose is intrinsically unstable with an increased number of repeats (average 8, compared with 2 for controls, P<10(-8)). We conclude that the HREM has a single founder and is the most common mutation in familial and sporadic ALS in Europe.
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| 2. |
- Alafuzoff, Irina, et al.
(författare)
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Assessment of beta-amyloid deposits in human brain : a study of the BrainNet Europe Consortium
- 2009
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Ingår i: Acta Neuropathologica. - : Springer Science and Business Media LLC. - 0001-6322 .- 1432-0533. ; 117:3, s. 309-320
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Tidskriftsartikel (refereegranskat)abstract
- beta-Amyloid (A-beta) related pathology shows a range of lesions which differ both qualitatively and quantitatively. Pathologists, to date, mainly focused on the assessment of both of these aspects but attempts to correlate the findings with clinical phenotypes are not convincing. It has been recently proposed in the same way as iota and alpha synuclein related lesions, also A-beta related pathology may follow a temporal evolution, i.e. distinct phases, characterized by a step-wise involvement of different brain-regions. Twenty-six independent observers reached an 81% absolute agreement while assessing the phase of A-beta, i.e. phase 1 = deposition of A-beta exclusively in neocortex, phase 2 = additionally in allocortex, phase 3 = additionally in diencephalon, phase 4 = additionally in brainstem, and phase 5 = additionally in cerebellum. These high agreement rates were reached when at least six brain regions were evaluated. Likewise, a high agreement (93%) was reached while assessing the absence/presence of cerebral amyloid angiopathy (CAA) and the type of CAA (74%) while examining the six brain regions. Of note, most of observers failed to detect capillary CAA when it was only mild and focal and thus instead of type 1, type 2 CAA was diagnosed. In conclusion, a reliable assessment of A-beta phase and presence/absence of CAA was achieved by a total of 26 observers who examined a standardized set of blocks taken from only six anatomical regions, applying commercially available reagents and by assessing them as instructed. Thus, one may consider rating of A-beta-phases as a diagnostic tool while analyzing subjects with suspected Alzheimer's disease (AD). Because most of these blocks are currently routinely sampled by the majority of laboratories, assessment of the A-beta phase in AD is feasible even in large scale retrospective studies.
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| 3. |
- Alafuzoff, Irina, et al.
(författare)
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Neuropathological assessments of the pathology in frontotemporal lobar degeneration with TDP43-positive inclusions : an inter-laboratory study by the BrainNet Europe consortium
- 2015
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Ingår i: Journal of neural transmission. - : Springer Science and Business Media LLC. - 0300-9564 .- 1435-1463. ; 122:7, s. 957-972
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Tidskriftsartikel (refereegranskat)abstract
- The BrainNet Europe consortium assessed the reproducibility in the assignment of the type of frontotemporal lobar degeneration (FTLD) with TAR DNA-binding protein (TDP) 43 following current recommendations. The agreement rates were influenced by the immunohistochemical (IHC) method and by the classification strategy followed. p62-IHC staining yielded good uniform quality of stains, but the most reliable results were obtained implementing specific Abs directed against the hallmark protein TDP43. Both assessment of the type and the extent of lesions were influenced by the Abs and by the quality of stain. Assessment of the extent of the lesions yielded poor results repeatedly; thus, the extent of pathology should not be used in diagnostic consensus criteria. Whilst 31 neuropathologists typed 30 FTLD-TDP cases, inter-rater agreement ranged from 19 to 100 per cent, being highest when applying phosphorylated TDP43/IHC. The agreement was highest when designating Type C or Type A/B. In contrast, there was a poor agreement when attempting to separate Type A or Type B FTLD-TDP. In conclusion, we can expect that neuropathologist, independent of his/her familiarity with FTLD-TDP pathology, can identify a TDP43-positive FTLD case. The goal should be to state a Type (A, B, C, D) or a mixture of Types (A/B, A/C or B/C). Neuropathologists, other clinicians and researchers should be aware of the pitfalls whilst doing so. Agreement can be reached in an inter-laboratory setting regarding Type C cases with thick and long neurites, whereas the differentiation between Types A and B may be more troublesome.
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| 4. |
- Kovacs, Gabor G, et al.
(författare)
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Neuropathology of the hippocampus in FTLD-Tau with Pick bodies : A study of the BrainNet Europe Consortium
- 2013
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Ingår i: Neuropathology and Applied Neurobiology. - : Wiley. - 0305-1846 .- 1365-2990. ; 39:2, s. 166-178
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Tidskriftsartikel (refereegranskat)abstract
- Aims: Frontotemporal lobar degeneration with Pick bodies (Pick's disease) is characterized by the presence of tau immunoreactive spherical structures in the cytoplasm of neurons. In view of confusion about the molecular pathology of Pick's disease, we aimed to evaluate the spectrum of tau pathology and concomitant neurodegeneration-associated protein depositions in the characteristically affected hippocampus. Methods: We evaluated immunoreactivity for tau (AT8, 3R, 4R), α-synuclein, TDP43, p62, and ubiquitin in the hippocampus, entorhinal and temporal cortex in 66 archival cases diagnosed neuropathologically as Pick's disease. Results: Mean age at death was 68.2 years (range 49 to 96). Fifty-two (79%) brains showed 3R immunoreactive spherical inclusions in the granule cells of the dentate gyrus. These typical cases presented mainly with the behavioural variant of FTD, followed by progressive aphasia, mixed syndromes or early memory disturbance. α-Synuclein immunoreactivity was seen only in occasional spherical tau-positive inclusions, TDP-43 IR was absent, and 4R IR was present only as neurofibrillary tangles in pyramidal neurons. Aβ immunoreactivity was observed in 16 cases; however, the overall level of Alzheimer's disease-related alterations was mainly low or intermediate (n = 3). Furthermore, we identified six cases with unclassifiable tauopathy. Conclusions: 1) Pick's disease may occur also in elderly patients and is characterized by a relatively uniform pathology with 3R tau inclusions particularly in the granule cells of dentate gyrus; 2) even minor deviation from these morphological criteria suggests a different disorder; and 3) immunohistological revision of archival cases expands the spectrum of tauopathies that require further classification.
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