| Gene Symbol | protein |
| Chromosome | 4p16.3 |
| Gene | HTT (Huntingtin) located on chromosome 4p16.3 |
| Protein | Huntingtin (HTT), ~3,144 amino acids (~350 kDa) |
| Normal function | Involved in neuronal development, vesicle trafficking, transcription regulation |
| Normal | ≤26 CAG repeats |
| Intermediate | 27-35 repeats (may expand in offspring) |
| Disease-causing | ≥36 repeats (fully penetrant) |
| Juvenile onset | ≥60 repeats (often paternal inheritance) |
| RT-QuIC | Detects mHTT aggregates in CSF with 80-90% sensitivity |
| PMCA | Amplifies pathological conformers for detection |
| Applications | Pre-symptomatic carrier identification, disease staging |
| KG Connections | 5 knowledge graph edges |
| Databases | GeneCardsUniProtNCBI GeneHPASTRING |