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| 2. |
- Majounie, Elisa, et al.
(författare)
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Frequency of the C9orf72 hexanucleotide repeat expansion in patients with amyotrophic lateral sclerosis and frontotemporal dementia: a cross-sectional study
- 2012
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Ingår i: Lancet Neurology. - 1474-4465. ; 11:4, s. 323-330
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Tidskriftsartikel (refereegranskat)abstract
- Background We aimed to accurately estimate the frequency of a hexanucleotide repeat expansion in C9orf72 that has been associated with a large proportion of cases of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Methods We screened 4448 patients diagnosed with ALS (El Escorial criteria) and 1425 patients with FTD (Lund-Manchester criteria) from 17 regions worldwide for the GGGGCC hexanucleotide expansion using a repeat-primed PCR assay. We assessed familial disease status on the basis of self-reported family history of similar neurodegenerative diseases at the time of sample collection. We compared haplotype data for 262 patients carrying the expansion with the known Finnish founder risk haplotype across the chromosomal locus. We calculated age-related penetrance using the Kaplan-Meier method with data for 603 individuals with the expansion. Findings In patients with sporadic ALS, we identified the repeat expansion in 236 (7.0%) of 3377 white individuals from the USA, Europe, and Australia, two (4.1%) of 49 black individuals from the USA, and six (8.3%) of 72 Hispanic individuals from the USA. The mutation was present in 217 (39.3%) of 552 white individuals with familial MS from Europe and the USA. 59 (6.0%) of 981 white Europeans with sporadic FTD had the mutation, as did 99 (24.8%) of 400 white Europeans with familial FTD. Data for other ethnic groups were sparse, but we identified one Asian patient with familial ALS (from 20 assessed) and two with familial FTD (from three assessed) who carried the mutation. The mutation was not carried by the three Native Americans or 360 patients from Asia or the Pacific Islands with sporadic MS who were tested, or by 41 Asian patients with sporadic FTD. All patients with the repeat expansion had (partly or fully) the founder haplotype, suggesting a one-off expansion occurring about 1500 years ago. The pathogenic expansion was non-penetrant in individuals younger than 35 years, 50% penetrant by 58 years, and almost fully penetrant by 80 years. Interpretation A common Mendelian genetic lesion in C9472 is implicated in many cases of sporadic and familial ALS and FTD. Testing for this pathogenic expansion should be considered in the management and genetic counselling of patients with these fatal neurodegenerative diseases.
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- Dillman, AA, et al.
(författare)
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Transcriptomic profiling of the human brain reveals that altered synaptic gene expression is associated with chronological aging
- 2017
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Ingår i: Scientific reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 7:1, s. 16890-
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Tidskriftsartikel (refereegranskat)abstract
- Aging is a biologically universal event, and yet the key events that drive aging are still poorly understood. One approach to generate new hypotheses about aging is to use unbiased methods to look at change across lifespan. Here, we have examined gene expression in the human dorsolateral frontal cortex using RNA- Seq to populate a whole gene co-expression network analysis. We show that modules of co-expressed genes enriched for those encoding synaptic proteins are liable to change with age. We extensively validate these age-dependent changes in gene expression across several datasets including the publically available GTEx resource which demonstrated that gene expression associations with aging vary between brain regions. We also estimated the extent to which changes in cellular composition account for age associations and find that there are independent signals for cellularity and aging. Overall, these results demonstrate that there are robust age-related alterations in gene expression in the human brain and that genes encoding for neuronal synaptic function may be particularly sensitive to the aging process.
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- Englund, Elisabet, et al.
(författare)
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Familial Lund frontotemporal dementia caused by C9ORF72 hexanucleotide expansion.
- 2012
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Ingår i: Neurobiology of Aging. - : Elsevier BV. - 1558-1497 .- 0197-4580.
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Tidskriftsartikel (refereegranskat)abstract
- Frontotemporal dementia (FTD) as an important clinical entity was rediscovered in Lund and Manchester in the early 1990s. Here we show that the large Lund pedigree with behavioral variant of frontotemporal dementia previously described with this disorder has an expansion in the recently described C9ORF72 locus on chromosome 9.
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