Table 1.

Patients’ and controls’ characteristics

	SCA3	SCA3 controls	SCA6	SCA6 controls	FRDA	FRDA controls
Number of males/females	12/18	8/22	12/2	11/3	11/9	12/8
Mean age ± SD (yrs)	50.5 ± 12.9	51.1 ± 13.1	62.3 ± 13.0	62.0 ± 12.7	40.2 ± 16.0	40.4 ± 17.2
	U = 443.5, p = 0.923		U = 96.0, p = 0.946		U = 199.0, p = 0.989
Mean years of education ± SD	15.5 ± 3.3	15.5 ± 2.9	16.0 ± 3.0	15.6 ± 3.3	16.2 ± 3.0	16.2 ± 3.1
	U = 431.0, p = 0.777		U = 88.0, p = 0.667		U = 192.5, p = 0.841
Mean age at disease onset ± SD (yrs)	39.5 ± 11.7	–	53.0 ± 12.4	–	20.7 ± 12.3	–
Mean disease duration ± SD (yrs)	11.0 ± 8.2	–	10.0 ± 11.8	–	19.5 ± 10.6	–
Mean SARA score ± SD	12.9 ± 7.5	–	10.8 ± 5.9		20.4 ± 7.7
Mean repeat length of expanded alleles ± SD (number of patients with known repeat length)	69 ± 4 (n = 23)	–	22 ± 2 (n = 11)	–	Longer allele: 730 ± 225; Shorter allele: 480 ± 245 (n = 19)	–

Statistics: Two-sided Mann–Whitney U tests were applied to test for age and level of education differences between the patient and corresponding control groups

SCA3 spinocerebellar ataxia type 3, SCA6 spinocerebellar ataxia type 6, FRDA Friedreich’s ataxia, SD standard deviation, SARA scale for the assessment and rating of ataxia, yrs years, n number