Baseline motor, behavioral, and cognitive characteristics of the COHORT population by group.

<p>Values are listed as mean (standard deviation) unless otherwise noted.</p><p>COHORT = Cooperative Huntington Observational Research Trial; HD = Huntington disease; (CAG)_n = cytosine-adenine-guanine repeat length in the <i>Huntingtin</i> allele; UHDRS = Unified Huntington's Disease Rating Scale.</p><p>*P-values refer to overall tests of heterogeneity across all six groups.</p><p>**For motor and behavioral measures, higher scores reflect greater impairment. For cognitive, independence, and functional measures, higher scores reflect less impairment.