Dystrophin pre-mRNA exon 6 splicing regulatory region (DMD exon 6 SRR)

The DMD pre-mRNA exon 6 splicing regulatory region refers to the specific sequences within the dystrophin gene's primary transcript that govern the inclusion of exon 6 during the splicing process. This region contains critical motifs, such as exonic splicing enhancers (ESEs), which are recognized by the spliceosome and auxiliary proteins to ensure accurate mRNA maturation. In the context of Duchenne muscular dystrophy (DMD), mutations involving exon 6—most notably exon 6 duplications—disrupt the reading frame of the DMD gene, leading to a complete lack of functional dystrophin protein and subsequent progressive muscle degeneration. This regulatory region serves as a therapeutic target for antisense oligonucleotides (ASOs), such as the investigational drug NS-089/NCNP-02. By binding to these specific regulatory sequences, ASOs can induce 'exon skipping,' effectively bypassing the mutated or duplicated exon 6 during splicing. This intervention restores the mRNA reading frame, enabling the synthesis of a shorter but partially functional dystrophin protein, which is intended to transition the severe DMD phenotype toward a milder Becker muscular dystrophy (BMD) phenotype. Clinical development in this area focuses on optimizing the efficiency of exon 6 exclusion to maximize dystrophin restoration in affected muscle tissues.

Other names

DMD exon 6Dystrophin exon 6DMD exon 6 splicing signalsDMD exon 6 exonic splicing enhancer

Antisense oligonucleotides bind to specific splicing regulatory sequences (such as exonic splicing enhancers) within or adjacent to exon 6 of the DMD pre-mRNA. This binding sterically hinders the splicing machinery, leading to the exclusion (skipping) of exon 6 from the mature mRNA transcript. In patients with specific mutations, such as exon 6 duplications or deletions that disrupt the reading frame, skipping exon 6 (or adjacent exons) can restore the open reading frame, allowing for the production of a truncated but functional dystrophin protein.