Elucidating the role of m6A in Fragile X-associated tremor/ataxia syndrome

Fragile X-associated tremor/ataxia syndrome (FXTAS) is a progressive, late-onset neurodegenerative disorder affecting carriers of CGG premutation expansions (55–200 repeats) in the FMR1 gene. The condition is marked by tremor, gait ataxia, Parkinsonism, and cognitive decline, with neuropathological features such as intranuclear inclusions and Purkinje cell loss. While disease mechanisms such as toxic RNA gain-of-function and repeat- associated non-AUG (RAN) translation have been implicated in FXTAS pathogenesis, the post-transcriptional regulatory landscape, particularly the role of RNA modifications, remains poorly defined and largely unexplored in the context of FXTAS and neurodegeneration in general. Thus, the epitranscriptome represents a new dimension of regulation that could be critical in our understanding of FXTAS and neurodegenerative disease in general. This project investigates N6-methyladenosine (m6A), a highly prevalent RNA modification in the brain, in the context of FXTAS. m6A dynamically regulates RNA stability, translation, and localization, and is critical in many brain functions. Our long-term goals are to elucidate the role of m6A dysregulation in affecting key molecular pathways and neurodegeneration, thereby translating our results into clinically relevant strategies for the improved treatment of FXTAS and shared mechanisms of neurodegenerative diseases. Our exciting preliminary studies show (1) significant changes in m6A regulatory proteins and methylation patterns in FXTAS models, and (2) demonstrate that genetic disruption of the m6A pathway worsens CGG repeat-induced neurotoxicity in Drosophila. We hypothesize that m6A dysregulation plays a fundamental role in driving FXTAS pathogenesis by affecting key molecular and neuropathological changes. Aim 1 will define the m6A epitranscriptomic landscape in postmortem FXTAS and control human cortex tissue using m6A-CAM-seq (which provides single-nucleotide resolution m6A) and traditional m6A-seq. Changes in m6A will be integrated with changes in transcriptomic and proteomic data from the same samples to identify functionally important genes and pathways affected by m6A in FXTAS. Aim 2 will assess the functional impact of m6A pathway disruption in vivo by crossing m6A enzyme knockout mice with a CGG-repeat FXTAS mouse model and evaluating behavioral, neuropathological, and molecular phenotypes. By integrating our genomic, genetic and molecular findings will provide unique mechanistic insights on how m6A modifications could drive FXTAS pathogenesis, which have the potential for discovering new molecular targets with relevant clinical, translational, and therapeutic implications. This innovative study will be the first to define the role of m6A in FXTAS, offering new insights into disease mechanisms and potentially revealing new, widely applicable targets relevant to a broad class of neurodegenerative diseases. Project Number: 1R21AG101124-01 | Fiscal Year: 2026 | NIH Institute/Center: National Institute on Aging (NIA) | Principal Investigator: Andrew Shafik (+1 co-PI) | Institution: EMORY UNIVERSITY, ATLANTA, GA | Award Amount: $430,375 | Activity Code: R21 | Study Section: Special Emphasis Panel[ZRG1 AN-Q (55)] View on NIH RePORTER: https://reporter.nih.gov/project-details/11356174