Expanded CTG repeat RNA foci

Expanded CTG repeat RNA foci are abnormal nuclear aggregates formed by RNAs containing excessive CTG repeats, as seen especially in myotonic dystrophy type 1. These foci arise due to the ability of long CTG repeat tracts to fold into stable hairpin structures, recruiting various RNA-binding proteins (notably MBNL1, MBNL2, and others) and sequestering them in the nucleus. This sequestration alters normal RNA splicing, retention, and metabolism, initiating a toxic gain-of-function effect. Clinically, such foci underpin multisystem pathology in DM1 and other repeat expansion diseases. Therapeutic strategies aim to dissolve these foci or prevent their formation, including novel small molecules, antisense RNAs, and genome editing approaches.

Other names

Expanded CUG repeat RNA fociCUG RNA nuclear fociNuclear RNA fociRibonuclear inclusionsCTG repeat RNA aggregates

Disruption or dissolution of RNA foci (by blocking secondary structure formation or repeat RNA-protein interactions); inhibition of toxic gain-of-function by reducing protein sequestration; genome editing to reduce CTG repeat length