Loss-of-function variants in RNA binding motif proteinX-linked induce neuronal defects contributing toamyotrophic lateral sclerosis pathogenesis

Despite being one of the most prevalent RNA modifications, the role of N6-methyladenosine (m6A) in amyotrophic lateral sclerosis (ALS) remains ambiguous. In this investigation,we explore the contribution of genetic defects of m6A-related genes to ALS pathogenesis.We scrutinized the mutation landscapeof m6A genes thr ough a comprehensive analysis of whole-exome sequencing cohorts, encompassing 508 ALS patients and 1660 population-matched controls. Our findings reveal a noteworthy enrichment of RNA binding motif proteinX-linked (RBMX) variants amo ng ALS patients, with a significant correlation between pathogenic m6A variants and adverse clinical outcomes. Furthermore,Rbmx knockdown in NSC-34 cells overexpressing mutant TDP43Q331K results in cell death mediated by an augmented p53 response. Similarly, RBMX knockdown in ALSmotor neurons derived frominduced pluripotent stem cells (iPSCs) manifests morphological defects and activation of the p53 pathway. Transcriptional analysis using publicly available single-cell sequencing data from the primarymotor cortex indicates that RBMX-regulated genes selectively influence excitatory neurons and exhibit enrichment in ALS-implicated pathways. Through integrated analyses, our study underscores the emerging roles played by RBMXin ALS, suggesting a potential nexus between the disease and dysregulated m6A-mediated mRNA metabolism.