Dystrophin (DMD) gene exon 20 (DMD Exon 20)

The duplicated exon 20 region of the DMD gene is a specific genetic locus within the dystrophin gene that, when duplicated, typically causes Duchenne muscular dystrophy (DMD). The DMD gene encodes dystrophin, a protein essential for protecting muscle fibers from damage during contraction by linking the internal actin cytoskeleton to the extracellular matrix (UniProt P11532). A duplication of exon 20 often shifts the translational reading frame, leading to a premature stop codon and a complete lack of functional dystrophin protein (NIH/GARD). This region is a therapeutic target for antisense oligonucleotides (ASOs) that utilize an exon-skipping mechanism to restore the reading frame. Drugs like NS-089/NCNP-02 are designed to bind to the pre-mRNA of the duplicated exon 20, causing the splicing machinery to skip one copy of the exon (NS Pharma). This restoration allows for the synthesis of a functional, albeit potentially truncated, dystrophin protein, which can mitigate the disease phenotype and slow muscle degeneration (PubMed PMID: 33035308). Clinical monitoring of this target involves assessing dystrophin levels in muscle tissue and evaluating motor function through standardized tests (PubMed PMID: 29154442).

Other names

DMD exon 20Dystrophin exon 20Exon 20 duplicationDMD exon 20 region

Antisense oligonucleotide-mediated exon skipping to restore the translational reading frame