| Inheritance | Autosomal dominant |
| CAG Repeat Threshold | >60 repeats (classic JHD definition); sometimes >55 in broader definitions |
| Parental Origin | ~80% paternal (vs ~50% in adult HD) |
| Anticipation | Strong; longer repeats expand more during spermatogenesis |
| Chromosome | 4p16.3 (HTT gene) |
| Protein | Huntingtin (3,142 amino acids) |
| Databases | OMIMOrphanetClinicalTrialsPubMed |