| Inheritance | Autosomal dominant |
| Gene | *JPH3* (junctophilin-3) |
| Mutation Type | CGG trinucleotide repeat expansion in the 5' UTR |
| Chromosomal Location | 16q24.3 |
| Normal Repeat | 6-27 CGG repeats |
| Pathogenic Repeat | 41-58+ CGG repeats |
| RNA-mediated toxicity | Expanded CGG repeats may form toxic RNA structures that sequester essential RNA-binding proteins |
| Loss of JPH3 function | Junctophilin-3 is involved in calcium homeostasis at the endoplasmic reticulum-mitochondria contact sites |
| Age of onset | Typically 30-50 years, but can range from early 20s to late 60s |
| Disease duration | 10-20 years from symptom onset to death |
| Progression | Gradual decline in motor and cognitive function |
| Databases | OMIMOrphanetClinicalTrialsPubMed |