Publications by authors named "Catherine Schramm"

Background: The SorLA protein, encoded by the Sortilin-related receptor 1 (SORL1) gene, is a major player in Alzheimer's disease (AD) pathophysiology. Functional studies demonstrated that SorLA deficiency results in increased production of Aβ peptide, and thus a higher risk of AD. SorLA can be subject to proteolytic shedding at the cell surface, leading to the release of the soluble ectodomain of the protein (sSorLA) in the extracellular space.

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Purpose: Describe clinical characteristics and outcome of Li-Fraumeni syndrome (LFS)-associated osteosarcomas.

Methods: TP53 germline pathogenic/likely pathogenic variant carriers diagnosed with osteosarcoma in France between 1980 and 2019 were identified via the French Li-Fraumeni database at Rouen University Hospital. Sixty-five osteosarcomas in 52 patients with available clinical and histological data were included.

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Purpose: To assess the likely pathogenic/pathogenic (LP/P) variants rates in Mendelian dementia genes and the moderate-to-strong risk factors rates in patients with Alzheimer disease (AD).

Methods: We included 700 patients in a prospective study and performed exome sequencing. A panel of 28 Mendelian and 6 risk-factor genes was interpreted and returned to patients.

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Article Synopsis
  • Alzheimer disease (AD) is influenced by genetic factors, particularly loss-of-function (LoF) variants of the SORL1 gene, which increase the risk of developing AD; assessing how these variants affect individuals as they age is crucial for genetic counseling and preventive measures.* -
  • The researchers developed a method to estimate the age-related risk of SORL1-LoF variants by analyzing data from a large study and an extended family dataset, considering the additional risk factor of the APOE-ε4 genotype.* -
  • Results indicated that by age 70, 100% of APOE-ε4ε4 carriers with SORL1-LoF variants are expected to develop AD, highlighting the need to consider
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  • The SorLA protein, linked to Alzheimer's disease, becomes dysfunctional when specific rare variants of the SORL1 gene are present, leading to increased production of harmful Aβ peptides.
  • 15 missense variants were identified through screening that impaired the maturation and trafficking of SorLA protein, with three variants (R332W, S577P, R654W) showing significant maturation defects in further studies.
  • These variants were found to hinder SorLA from reaching the cell surface, resulting in elevated Aβ secretion and a potential direct association with Alzheimer's pathology, influenced by changes in the protein's 3D structure.
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  • Pathogenic variants in the MYT1L gene lead to a neurodevelopmental disorder characterized by features like developmental delays, intellectual disabilities, and behavioral disorders.
  • A study analyzed genetic data from 40 previously unreported patients, adding to a total of 62 patients to better understand the clinical characteristics and genotype-phenotype correlations.
  • The research confirmed key phenotypic traits, introduced new clinical features, and emphasized that patients with certain genetic variants do not show distinct clinical differences, aiding in improved diagnosis and management of the disorder.
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Many copy number variants (CNVs) confer risk for the same range of neurodevelopmental symptoms and psychiatric conditions including autism and schizophrenia. Yet, to date neuroimaging studies have typically been carried out one mutation at a time, showing that CNVs have large effects on brain anatomy. Here, we aimed to characterize and quantify the distinct brain morphometry effects and latent dimensions across 8 neuropsychiatric CNVs.

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Microduplications of the 17q21.31 chromosomal region encompassing the MAPT gene, which encodes the Tau protein, were identified in patients with a progressive disorder initially characterized by severe memory impairment with or without behavioral changes that can clinically mimic Alzheimer disease. The unique neuropathological report showed a primary tauopathy, which could not be unanimously classified in a given known subtype, showing both 4R- and 3R-tau inclusions, mainly within temporal cortical subregions and basal ganglia, without amyloid deposits.

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  • Genomic copy number variants (CNVs), particularly deletions and duplications, have been linked to cognitive ability, but their specific effects on intelligence are still not fully understood, especially for duplications.
  • The study involved analyzing CNVs from over 24,000 individuals and used statistical models to show that deletions decrease intelligence more significantly than duplications, with certain genes being intolerant to haploinsufficiency playing a key role.
  • The findings indicate that while a small fraction of genes has a significant negative impact on intelligence, the overall effects on cognition may stem from complex interactions within the genome rather than just a few specific pathways.
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16p11.2 and 22q11.2 Copy Number Variants (CNVs) confer high risk for Autism Spectrum Disorder (ASD), schizophrenia (SZ), and Attention-Deficit-Hyperactivity-Disorder (ADHD), but their impact on functional connectivity (FC) remains unclear.

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Article Synopsis
  • * Analyzed CNVs from autism and unselected populations using specific statistical models, finding that "probability of loss-of-function intolerance" (pLI) largely predicts the impacts on IQ and autism vulnerability.
  • * Concluded that deletions of CNVs significantly lower IQ and increase autism risk, while duplications have a smaller effect on IQ and are less related to autism susceptibility; the study highlights the complex genetic contributions to autism.
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  • Estimating the effects of copy-number variations (CNVs) on phenotypes like IQ is difficult due to the rarity and uniqueness of many CNVs, making individual studies challenging.* -
  • Recent research indicates that combining genomic annotations, such as the pLI score, can predict IQ loss but only provides indirect estimates of CNV effects.* -
  • The new approach, called HBIQ, uses hierarchical Bayesian models to directly assess the impact of rare CNVs on intelligence, revealing significant deleterious effects on IQ and improving prediction accuracy over previous methods.*
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The seven human 14-3-3 proteins are encoded by the YWHA-gene family. They are expressed in the brain where they play multiple roles including the modulation of synaptic plasticity and neuronal development. Previous studies have provided arguments for their involvement in schizophrenia, but their role during disease onset is unknown.

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  • - A study analyzed more than 2,600 serovars of bacteria to explore the links between genetic differences and their ability to cause disease, aiming to create a predictive model for virulence.
  • - Researchers evaluated 35 strains from the SalFoS collection using various infection models, including tests on human cells and mice, to identify signs of virulence and correlate them with genomic data.
  • - Findings revealed significant correlations in virulence predictions based on genomic information, providing a new strategy for assessing risks and monitoring bacterial strains linked to foodborne illnesses.
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Recurrent events arise when an event occurs many times for a subject. Many models have been developed to analyze these kind of data: the Andersen-Gill's model is one of them as well as the Prentice-William and the Peterson's model, the Wei Lee and Weissfeld's model, or even frailty models, all assuming an independent and noninformative censoring. However, in practice, these assumptions may be violated by the existence of a terminal event that permanently stops the recurrent process (eg, death).

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  • The striatum is involved in language processing, but its exact role remains unclear, prompting this study using Huntington's disease as a model for striatal damage.
  • The study found that early Huntington's disease patients performed poorly on a linguistic task, indicating a specific impairment linked to changes in how they select between different grammatical options.
  • Further analysis showed that this impairment relates to increased randomness in selecting grammatical choices, correlating with degeneration in the dorsal striatum, suggesting a role similar to that in motor and cognitive selection processes.
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Importance;: Copy number variants (CNVs) classified as pathogenic are identified in 10% to 15% of patients referred for neurodevelopmental disorders. However, their effect sizes on cognitive traits measured as a continuum remain mostly unknown because most of them are too rare to be studied individually using association studies.

Objective: To measure and estimate the effect sizes of recurrent and nonrecurrent CNVs on IQ.

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Little is known about the genetic factors modulating the progression of Huntington's disease (HD). Dopamine levels are affected in HD and modulate executive functions, the main cognitive disorder of HD. We investigated whether the Val158Met polymorphism of the catechol-O-methyltransferase (COMT) gene, which influences dopamine (DA) degradation, affects clinical progression in HD.

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Heterogeneity in treatment efficacy is a major concern in clinical trials. Clustering may help to identify the treatment responders and the non-responders. In the context of longitudinal cluster analyses, sample size and variability of the times of measurements are the main issues with the current methods.

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The retest effect-improvement of performance on second exposure to a task-may impede the detection of cognitive decline in clinical trials for neurodegenerative diseases. We assessed the impact of the retest effect in Huntington's disease trials, and investigated its possible neutralization. We enrolled 54 patients in the Multicentric Intracerebral Grafting in Huntington's Disease (MIG-HD) trial and 39 in the placebo arm of the Riluzole trial in Huntington's Disease (RIL-HD).

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  • The study investigates how different characteristics of cord blood influence their use and explores banking strategies to assess financial sustainability and therapeutic outcomes for public cord blood banks struggling financially.
  • A retrospective analysis was conducted on 9,396 cord blood units from banks in France, Germany, and the USA, focusing on factors like ethnic background and cell counts to develop a Utilization Score for transplantation likelihood.
  • Findings show that while the least selective banking strategy (Scenario A) provided the highest number of transplants, it also resulted in the largest financial deficit, while a more selective strategy (Scenario C) achieved a balance with fewer transplants and a significantly reduced deficit.
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Background And Objectives: Serious medication administration errors are common in hospitals. Various interventions, including barcode-based technologies, have been developed to help prevent such errors. This systematic review and this meta-analysis focus on the efficacy of interventions for reducing medication administration errors.

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We aimed to clarify the role of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) in the management of large-vessel vasculitis (LVV), focusing on 3 issues which are as follows: describe and determine the different FDG-PET criteria for the diagnosis of vascular inflammation, the performance of FDG-PET for the diagnosis of large-vessel inflammation in giant cell arteritis (GCA) patients, and the performance of FDG-PET to evaluate the disease inflammatory activity in Takayasu arteritis (TA) patients. MEDLINE, Cochrane Library, and EMBASE database were searched for articles that evaluated the value of FDG-PET in LVV, from January 2000 to December 2013. Inclusion criteria were American College of Rheumatology criteria for GCA or TA, definition PET positivity threshold, and >4 cases included.

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Toll-like receptors (TLR) recognize pathogen molecules and danger-associated signals that stimulate inflammatory processes. TLRs have been studied mainly in antigen-presenting cells, where they exert important immune regulatory functions, but they are also expressed by epithelial tumor cells, where they have been implicated in tumor progression. In this study, we demonstrate that the injection of TLR7 agonist in NOD/SCID mice, in C57BL/6 wild-type, and TLR7-deficient mice grafted with lung adenocarcinoma tumor cells leads to increased tumor progression and chemotherapeutic resistance.

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