Table 1.

The demographic features of SCA3 participants in different ethnicities

	Caucasian	African American	Asian #	p-value for three ethnicities	p-value for two ethnicities
					Caucasians vs. African Americans	Caucasians vs. Asians	African Americans vs. Asians
Sample size, N (%)	66 (25.68%)	43 (16.73%)	148 (57.59%)	/
Gender, M : F	32 : 34	27 : 16	77 : 71	0.325a	0.143a	0.632a	0.212a
Age at first visit, Yr	52.42 ± 12.79 Median = 52.5	49.70 ± 11.34 Median = 50.0	45.05 ± 12. 54 Median = 44.5	0.000b	0.216c	0.000d	0.016c
Length of expanded CAG repeats in ATXN3, N	70.83 ± 4.62 Median = 71.0	71.09 ± 3.81 Median = 71.0	74.28 ± 3.87 Median = 74.0	0.000b	0.842c	0.000c	0.000c
Length of normal CAG repeats in ATXN3, N	22.35 ± 5.63 Median = 23.0	23.88 ± 6.73 Median = 23.0	19.81 ± 6.74 Median = 23.0	0.001b	0.188c	0.014c	0.001c
Disease duration, Yr	12.95 ± 7.38 Median = 12.0	12.98 ± 7.67 Median = 11.50	8.75 ± 5.64 Median = 8.0	0.000b	0.940c	0.000c	0.000c
Age at onset, Yr	39.47 ± 12.35	36.38 ± 11.25	36.32 ± 11.28	0.166e	0.531f	0.200f	1.000f
SARA score	14.27 ± 7.94 Median = 12.5	17.14 ± 9.25 Median = 17.0	12.85 ± 8.76 Median = 8.0	0.016b	0.114c	0.142c	0.004c
PHQ-9 score	7.88 ± 5.95 Median = 7.0	6.91 ± 5.72 Median = 6.0	6.65 ± 4.69 Median = 6.0	0.596b	0.353c	0.512c	0.928c

Abbreviations: F = Female, M = Male, N = Number, PHQ-9 = The 9-item Patient Health Questionnaire, SARA = Scale for Assessment and Rating of Ataxia, SCA = Spinocerebellar Ataxia, Yr = Year.

Values represent mean ± standard deviation or number, and for variables with non-normal distribution, the median is reported as well.

^#Composed with 131 SCA3 patients from Chinese cohort and 17 Asian American SCA3 patients from the CRC-SCA cohort. Since the Chinese patients had no PHQ-9 data, the value for the PHQ-9 score was only calculated from Asian Americans.

^aChi-square test

^bindependent samples Kruskal-Wallis tests

^cMann-Whitney U tests

^dStudent's independent samples t-test

^eanalysis of variance

^fTukey’s post hoc analyses