Publications by authors named "Sara Rollinson"

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  • * A study analyzed 4,685 sporadic FTD cases and found significant genetic variants at the MAPT and APOE loci that increase the risk for the disease, indicating potential genetic overlap with other neurodegenerative diseases.
  • * The genetic risk factors appear to vary by population, with MAPT and APOE associations predominantly found in Central/Nordic and Mediterranean Europeans, suggesting a need for further research into these population-specific features for better understanding of sporadic FTD.
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  • Multiple system atrophy (MSA) is a neurodegenerative disease that leads to symptoms like parkinsonism and ataxia, but its genetic causes are not well understood and treatment options are limited to supportive care.
  • A comprehensive study involving the whole genome sequencing of nearly 900 MSA patients and over 7,000 controls discovered four key genetic risk factors associated with the disease.
  • The research identified potential susceptibility genes and provided insights into how genetic variations influence gene expression in brain cells, offering a valuable resource for further studies on similar diseases.
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Background: An accurate status determination of breast cancer biomarkers (ER, PR, HER2, Ki67) is crucial for guiding patient management. The "gold standard" for assessing these biomarkers in FFPE tissue is IHC, which faces challenges in standardization and exhibits substantial variability. In this study, we compare the concordance of a new commercial RT-qPCR kit with IHC in determining BC biomarker status.

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A repeat expansion in C9orf72 is the major cause of both frontotemporal dementia and amyotrophic lateral sclerosis, accounting for approximately 1 in 12 cases of either disease. The expansion is translated to produce five dipeptide repeat proteins (DPRs) which aggregate in patient brain and are toxic in numerous models, though the mechanisms underlying this toxicity are poorly understood. Recent studies highlight nucleocytoplasmic transport impairments as a potential mechanism underlying neurodegeneration in C9orf72-linked disease, although the contribution of DPRs to this remains unclear.

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Importance: Juvenile amyotrophic lateral sclerosis (ALS) is a rare form of ALS characterized by age of symptom onset less than 25 years and a variable presentation.

Objective: To identify the genetic variants associated with juvenile ALS.

Design, Setting, And Participants: In this multicenter family-based genetic study, trio whole-exome sequencing was performed to identify the disease-associated gene in a case series of unrelated patients diagnosed with juvenile ALS and severe growth retardation.

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Objective: The precise relationship between frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) is incompletely understood. The association has been described as a continuum, yet data suggest that this may be an oversimplification. Direct comparisons between patients who have behavioural variant FTD (bvFTD) with and without ALS are rare.

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  • The study aimed to understand the relationship between genetic expansions, age at onset, and syndromic differences in frontotemporal lobar degeneration (FTLD) using a large European sample.
  • Researchers found that pathogenic expansions were more common in patients with behavioral variant frontotemporal dementia (bvFTD) compared to primary progressive aphasia (PPA), and there were notable differences based on genetic ancestry.
  • The findings suggest a link between genetic factors, ancestry, and the development of bvFTD, highlighting the complexity of genetic risk associated with this condition.
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  • * The study aimed to create transgenic mice with DPRs longer than 1000 repeats by using alternative codon sequences to minimize instability.
  • * Results showed that while the DPR inserts integrated into the mouse genome, they did not remain stable across generations, suggesting that using viral vectors post-birth might be a better strategy for delivering long repeats.
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Frontotemporal lobar degeneration with neuronal inclusions of the TAR DNA-binding protein 43 (FTLD-TDP) represents the most common pathological subtype of FTLD. We established the international FTLD-TDP whole-genome sequencing consortium to thoroughly characterize the known genetic causes of FTLD-TDP and identify novel genetic risk factors. Through the study of 1131 unrelated Caucasian patients, we estimated that C9orf72 repeat expansions and GRN loss-of-function mutations account for 25.

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  • * Researchers hypothesized that genetic factors, specifically common single nucleotide polymorphisms (SNPs), could influence DNA methylation changes that affect age of onset in C9orf72 patients.
  • * A study found a significant association between the SNP rs9357140 and age of onset for C9orf72 patients, with carriers of the A allele experiencing symptoms 6 years later than GG carriers—this pattern was also observed in a broader patient group without C9orf72 mutations. *
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  • Loss-of-function mutations in the GRN gene lead to a specific type of frontotemporal lobar degeneration (FTLD) characterized by TDP-43 pathology, but the age of onset and symptoms vary among patients, prompting research into genetic modifiers.
  • The study involved a multi-phase approach including discovery, replication, and meta-analysis to identify genetic variants that potentially influence disease risk and onset in individuals with GRN mutations.
  • Key findings included statistically significant variants at the GFRA2 locus, with further investigation showing effects on GFRA2 gene expression and interactions between GFRA2 and progranulin, highlighting their potential roles in the disease.
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  • - The study aimed to find new genes linked to ALS by conducting a genome-wide association study with over 20,000 ALS patients and nearly 60,000 controls, as well as a rare variant analysis comparing familial ALS cases to controls.
  • - Researchers identified KIF5A as a novel gene associated with ALS, noting that mutations in different regions of KIF5A are responsible for other neurodegenerative diseases, such as hereditary spastic paraplegia and Charcot-Marie-Tooth disease.
  • - Interestingly, ALS patients with certain loss-of-function mutations in KIF5A had longer survival compared to typical cases, suggesting a complex role of KIF5A mutations in ALS pathology and emphasizing the importance of cytoskeletal
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We have employed as 'gold standards' two in-house, well-characterised and validated polyclonal antibodies, C9-L and C9-S, which detect the longer and shorter forms of C9orf72, and have compared seven other commercially available antibodies with these in order to evaluate the utility of the latter as credible tools for the demonstration of C9orf72. C9-L and C9-S antibodies immunostained cytoplasmic 'speckles', and the nuclear membrane, respectively, in cerebellar Purkinje cells of the cerebellum in patients with behavioural variant frontotemporal dementia (bvFTD) with amyotrophic lateral sclerosis (ALS), and in patients with ALS alone. Similar staining was seen in Purkinje cells in healthy control tissues and in other neurodegenerative disorders, and in pyramidal cells of CA4 and dentate gyrus of hippocampus.

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Frontotemporal Lobar Degeneration (FTLD) encompasses certain related neurodegenerative disorders which alter personality and cognition. Heterogeneous ribonuclear proteins (hnRNPs) maintain RNA metabolism and changes in their function may underpin the pathogenesis of FTLD. Immunostaining for hnRNP E2 was performed on sections of frontal and temporal cortex with hippocampus from 80 patients with FTLD, stratified by pathology into FTLD-tau and FTLD-TDP type A, B and C subtypes, and by genetics into patients with C9orf72 expansions, MAPT or GRN mutations, or those with no known mutation, and on 10 healthy controls.

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Frontotemporal Lobar Degeneration (FTLD) encompasses certain related neurodegenerative disorders which alter behaviour, personality and language. Heterogeneous ribonuclear proteins (hnRNPs) maintain RNA metabolism and changes in their function may underpin the pathogenesis of FTLD. Immunostaining for hnRNP A1, A2/B1 and A3 was performed on sections of temporal cortex with hippocampus from 61 patients with FTLD, stratified by pathological hallmarks into FTLD-tau and FTLD-TDP type A, B and C subtypes, and by genetics into patients with C9orf72 expansions, MAPT or GRN mutations, or those without known mutation.

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Mitochondria play a key role in common neurodegenerative diseases and contain their own genome: mtDNA. Common inherited polymorphic variants of mtDNA have been associated with several neurodegenerative diseases, and somatic deletions of mtDNA have been found in affected brain regions. However, there are conflicting reports describing the role of rare inherited variants and somatic point mutations in neurodegenerative disorders, and recent evidence also implicates mtDNA levels.

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Given the central role of genetic factors in the pathogenesis of common neurodegenerative disorders, it is critical that mechanistic studies in human tissue are interpreted in a genetically enlightened context. To address this, we performed exome sequencing and copy number variant analysis on 1511 frozen human brains with a diagnosis of Alzheimer's disease (AD, n = 289), frontotemporal dementia/amyotrophic lateral sclerosis (FTD/ALS, n = 252), Creutzfeldt-Jakob disease (CJD, n = 239), Parkinson's disease (PD, n = 39), dementia with Lewy bodies (DLB, n = 58), other neurodegenerative, vascular, or neurogenetic disorders (n = 266), and controls with no significant neuropathology (n = 368). Genomic DNA was extracted from brain tissue in all cases before exome sequencing (Illumina Nextera 62 Mb capture) with variants called by FreeBayes; copy number variant (CNV) analysis (Illumina HumanOmniExpress-12 BeadChip); C9orf72 repeat expansion detection; and APOE genotyping.

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C9orf72 expansions are the most common genetic cause of FTLD and MND identified to date. Although being intronic, the expansion is translated into five different dipeptide repeat proteins (DPRs) that accumulate within patients' neurons. Attempts have been made to model DPRs in cell and animals.

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Mutations in progranulin (PGRN) have been linked to two neurodegenerative disorders, heterozygote mutations with frontotemporal lobar degeneration (FTLD) and homozygote mutations with neuronal ceroid lipofuscinosis (NCL). Human PGRN is 593aa secreted growth factor, made up of seven and a half repeats of a highly conserved granulin motif that is cleaved to produce the granulin peptides A-G and paragranulin. While it is thought that PGRN protects against neurodegeneration through its role in inflammation and tissue repair, the role of PGRN and granulins in the nervous system is currently unclear.

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It has been suggested that patients with motor neurone disease (MND) and those with MND combined with behavioural variant frontotemporal dementia (bvFTD) (ie FTD + MND) or with FTD alone might exist on a continuum based on commonalities of neuropathology and/or genetic risk. Moreover, it has been reported that both a neuronal and a glial cell tauopathy can accompany the TDP-43 proteinopathy in patients with motor neurone disease (MND) with cognitive changes, and that the tauopathy may be fundamental to disease pathogenesis and clinical phenotype. In the present study, we sought to substantiate these latter findings, and test this concept of a pathological continuum, in a consecutive series of 41 patients with MND, 16 with FTD + MND and 23 with FTD without MND.

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Our objective was to compare the clinical and pathological characteristics of frontotemporal dementia patients with MAPT, GRN and C9orf72 gene mutations. We carried out a cross-sectional comparative study of 74 gene-positive patients (15 MAPT, 17 GRN and 42 C9orf72). Thirty had post mortem pathological data permitting clinico-pathological correlation.

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Frontotemporal lobar degeneration is a highly familial disease and the most common known genetic cause is the repeat expansion mutation in the gene C9orf72. We have identified 2 brothers with an expansion mutation in C9orf72 using Southern blotting that is undetectable using repeat-primed polymerase chain reaction. Sequencing using high concentrations of DNA denaturants of a bacterial artificial chromosome clone obtained from one of the brothers identified a 10-base pair deletion adjacent to the expansion that presumably confers strong secondary structure that interferes with the genotyping.

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