Langbehn DR, Stout JC, Gregory S, et al. – In this study involving 2,065 visits from 443 candidates (mean age: 44.4 [10.3] years), researchers summarized decades-long early progression of Huntington disease (HD) and its dependence on CAG repeat length. They reported on motor-cognitive and white matter-ventricle measurements with comparable nonlinear trajectories across the period of the disease, and a powerful association with CAG. The striatum, on the other hand, suggested a near-linear trajectory with powerful CAG dependency, and gray matter demonstrated a slow, nonlinear pattern with weaker CAG dependency. This research may help in the understanding of the connection between brain changes and clinical manifestation in HD and their reliance on age and repeat length of CAG, which may be useful in clinical trials that modify disease.