Table I.

Demographic and baseline clinical data for the prodromal HD CAP groups (Low, Medium, High) and Controls.

	Controls (C)	Low (L)	Med (M)	High (H)	P-value and comparisons
Count	N = 225	N = 210	N = 274	N = 311
Demographics
Age (Mean ± SD; range)	43.9 ± 11.5; 19–84	35.0 ± 7.7; 20–57	41.0 ± 9.5; 26–72	44.2 ± 9.8; 18–76	<.0001; C,H> M>L
Gender (count)	143F, 82M	142F, 68M	182F, 92M	185F, 126M	0.1988
Education (Mean years; range)	14.7; 9–20	14.5; 8–20	14.4; 8–20	14.1; 8–20	0.1346
CAG Repeats (mean; range)	N/A	40.8; 38–45	42.2; 38–47	43.8; 39–61	<.0001; L< M< H
Estimated IQ (Mean ± SD; range)	113.4 ± 7.4; 90–133	112.5 ± 7.5; 75–127	112.1 ± 7.9; 84–127	111.8 ± 8.3; 75–128	0.1406
UHDRS Total Motor Score (TMS)
BASELINE (Mean ± SD; range)	2.7 ± 3.4; 0–22	2.9 ± 3.3; 0–18	4.1 ± 4.3; 0–25	6.8 ± 6.3; 0–35	<.0001; C,L< M< H
UHDRS Diagnosis Confidence Level (DCL)
BASELINE (Mean; range)	0.4; 0–2	0.6; 0–2	0.7; 0–3	1.1; 0–3	<.0001; C,L< M< H
BDI–II
BASELINE (Mean ± SD; range)	4.5 ± 5.3; 0–32	7.3 ± 8.3; 0–46	9.0 ± 9.1; 0–47	7.7 ± 8.7; 0–48	<.0001; C< L,H< M

Note: CAG, cytosine-adenine-guanine repeat (number of repeats > 40 is full penetrance); Estimated IQ, estimated full scale IQ; UHDRS, Unified Huntington’s Disease Rating Scale, Motor Score has max score 124; UHDRS Confidence Ratings (max score 4); BDI–II, Beck Depression Inventory II score (max score is 63, normal range 0–9); P-values are based on the test appropriate for the type of variable in question (e.g., chi-squared tests for categorical variables and ANOVA for continuous variables; see text).