A Translational Roadmap for Neurological Nonsense Mutation Disorders

Nonsense mutations, responsible for ~11% of gene lesions causing human monogenic diseases, introduce premature termination codons (PTCs) that lead to truncated proteins and nonsense-mediated mRNA decay (NMD). In the central nervous system (CNS), these mutations drive severe, progressive neurological conditions such as spinal muscular atrophy, Rett syndrome, and Duchenne muscular dystrophy. Readthrough therapies-strategies to override PTCs and restore full-length protein expression-have evolved from early aminoglycosides to modern precision tools including suppressor tRNAs, RNA editing, and CRISPR-based platforms. Yet clinical translation remains hampered by inefficient CNS delivery, variable efficacy, and the absence of personalized stratification. In this review, we propose a translational framework-the 4 Ds of Readthrough Therapy-to systematically address these barriers. The framework dissects the pipeline into Detection (precision patient identification and biomarker profiling), Delivery (engineered vectors for CNS targeting), Decoding (context-aware molecular correction), and Durability (long-term safety and efficacy). By integrating advances in machine learning, nanocarriers, base editing, and adaptive trial designs, this roadmap provides a structured strategy to bridge the translational gap. We advocate that a synergistic, modality-tailored approach will transform nonsense suppression from palliative care to durable, precision-based cures for once-untreatable neurological disorders.