Dystrophia Myotonica-Protein Kinase Transcript CUG Repeat Expansion (CUG Expansion)

The Dystrophia myotonica-protein kinase transcript CUG repeat expansion is a pathogenic molecular event underlying myotonic dystrophy type 1 (DM1). It involves the abnormal expansion of CTG trinucleotide repeats in the 3′ untranslated region (3′UTR) of the DMPK gene, leading to toxic gain-of-function effects at the RNA level. The expanded CUG repeat RNA forms stable secondary structures, accumulates in nuclear foci, and sequesters splicing factors like MBNL, causing widespread mis-splicing and contributing to disease pathology. While not a traditional receptor or enzyme, it is a therapeutic target due to its central role in DM1 pathogenesis.

Other names

Expanded CUG repeats in DMPK mRNADMPK 3'UTR CUG repeat expansionToxic CUG RNA

Engineered PPR proteins bind to expanded CUG-repeat RNAs, reducing RNA toxicity and restoring normal splicing activity.