TABLE 1.
Baseline characteristics of the SCA3 cohort.
| Full cohort | Subgroup with at least one follow-up | Statistics (χ2 or U) | P | |
| No. | 263 | 247 | NA | NA |
| No. of families | 165 | 155 | NA | NA |
| Women (%) | 138 (52.5%) | 131 (53.0%) | 0.02 | 0.898 |
| Age at baseline (years) | 44.67 ± 11.29 | 44.42 ± 10.81 | 32,140.00 | 0.838 |
| Age at onset (years) | 36.29 ± 10.22 | 36.15 ± 9.86 | 32,298.50 | 0.913 |
| Disease duration (years) | 8.38 ± 5.08 | 8.27 ± 5.10 | 31,985.50 | 0.765 |
| Length of expanded allele (repeat units) | 71.88 ± 3.43 | 71.83 ± 3.31 | 32,452.50 | 0.986 |
| Length of normal allele (repeat units)a | 19.98 ± 5.95 | 20.00 ± 5.99 | 32,224.50 | 0.999 |
| SARA score | 15.61 ± 7.94 | 15.45 ± 7.83 | 32,049.50 | 0.795 |
| INAS count | 4.84 ± 2.35 | 4.86 ± 2.36 | 32,347.50 | 0.936 |
| SCAFI scoreb | −0.35 ± 1.20 | −0.32 ± 1.19 | 19,581.00 | 0.857 |
Quantitative variables are given as mean ± SD; categorical variables as given as numbers (frequency); SARA, scale for the Assessment and Rating of Ataxia; INAS, inventory of non-ataxia signs. Length of expanded allele or normal allele refers to the CAG repeats in the ATXN3 gene.
aThere was a patient with homozygous ATXN3 mutation (with 67 CAG repeats on both allele), and this patient was excluded when calculating the mean and SD for length of normal allele (repeat units).
bSCAFI score was available in 204 patients of the full cohort, and 194 patients of the subgroup with at least one follow-up. The Mann-Whitney U test was used for the comparation of quantitative variables between groups, including age at baseline, age at onset, disease duration, length of expanded allele, length of normal allele, SARA score, INAS count, and SCAFI. The χ2 test for the comparation of gender between groups. After Bonferroni correction, only P-values < 0.0056 were considered significant.