Fragile X syndrome is a neurodevelopmental disorder that is caused by the silencing of a single gene on the X chromosome, the fragile X mental retardation 1 (FMR1) gene. Affected individuals display a unique neurocognitive phenotype that includes significant impairment in inhibitory control, selective attention, working memory, and visual-spatial cognition. In contrast, little is known about the trajectory and specificity of any cognitive impairment associated with the fragile X premutation (i.e., "carrier status") or its relationship with the recently identified neurodegenerative disorder, fragile X-associated tremor/ataxia syndrome (FXTAS). In the present study, we evaluated a broad sample of 40 premutation males (PM) aged 18-69 years matched on age and IQ to 67 unaffected comparison males (NC). Performance was compared across a range of cognitive domains known to be impaired in fragile X syndrome (i.e., "full mutation"). Tremor was also assessed using a self-report neurological questionnaire. PM displayed statistically significant deficits in their ability to inhibit prepotent responses, differentiating them from NC from age 30 onwards. With increasing age, the two groups follow different trajectories, with PM developing progressively more severe problems in inhibitory control. This deficit also has a strong co-occurrence in males displaying FXTAS-related symptomatology (p<.001). Selective attention was also impaired in PM but did not show any disproportionate aging effect. No other cognitive deficits were observed. We conclude that an inhibitory deficit and its impact across the lifespan are specifically associated with the fragile X premutation status, and may be a precursor for development of a more severe form of cognitive impairment or dementia, which has been reported in patients with the diagnosis of FXTAS.
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http://dx.doi.org/10.1016/j.cortex.2006.11.002 | DOI Listing |
Fragile X Syndrome (FXS) is characterized by intellectual impairment caused by CGG repeat expansion in the FMR1 gene. When repeats exceed 200, they induce DNA methylation of the promoter and the repeat region, resulting in transcriptional silencing of the FMR1 gene and the subsequent loss of FMRP protein. In the past decade or so, research has focused on the role of FMRP as an RNA-binding protein involved in translation inhibition in the brain in FXS model mice, particularly by slowing or stalling ribosome translocation on mRNA.
View Article and Find Full Text PDFProg Neuropsychopharmacol Biol Psychiatry
December 2024
Dept. Science, Roma Tre University, Rome, Italy; Neuroendocrinology, Metabolism and Neuropharmacology Unit, IRCCS Fondazione Santa Lucia, Rome, Italy. Electronic address:
β-Caryophyllene (BCP) is a naturally occurring sesquiterpene found in numerous plant species, including Cannabis sativa. BCP has shown a high safety profile and a wide range of biological functions, including beneficial effects in neurodegenerative and inflammatory diseases. Here, we used behavioral, pharmacological, and in-silico docking analyses to investigate the effects and mechanism of action of BCP in Fragile X Syndrome (FXS), the most common inherited cause of Autism Spectrum Disorder (ASD) and intellectual disability.
View Article and Find Full Text PDFJ Med Chem
December 2024
Medicines Discovery Institute, School of Biosciences, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, U.K.
LIMKs are serine/threonine and tyrosine kinases responsible for controlling cytoskeletal dynamics as key regulators of actin stability, ensuring synaptic health through normal synaptic bouton structure and function. However, LIMK1 overactivation results in abnormal dendritic synaptic development that characterizes the pathogenesis of Fragile X Syndrome (FXS). As a result, the development of LIMK inhibitors represents an emerging disease-modifying therapeutic approach for FXS.
View Article and Find Full Text PDFEffectively addressing ethical issues in precision medicine research in Africa requires a holistic social contract that integrates biomedical knowledge with local cultural values and Indigenous knowledge systems. Drawing on African epistemologies such as ubuntu and ujamaa and on our collective experiences in genomics and big data research for sickle cell disease, hearing impairment, and fragile X syndrome and the project Public Understanding of Big Data in Genomics Medicine in Africa, we envision a transformative shift in health research data governance in Africa that could help create a sense of shared responsibility between all stakeholders in genomics and data-driven health research in Africa. This shift includes proposing a social contract for genomics and data science in health research that is grounded in African communitarianism such as solidarity, shared decision-making, and reciprocity.
View Article and Find Full Text PDFAutism is clinically defined by challenges with social language, including difficulties offering on-topic language in a conversation. Similar differences are also seen in genetically related conditions such as fragile X syndrome (FXS), and even among those carrying autism-related genes who do not have clinical diagnoses (e.g.
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