A 3-year cohort study of the natural history of spinocerebellar ataxia type 6 in Japan

Table 1 Demographic, genetic, and clinical characteristics of the study population

	All patients	Male patients	Female patients
No.	46	23	23
Age at onset, y	48.0 ± 9.3 (31–66)	48.8 ± 10.0	47.2 ± 8.6
Age at registration, y	63.0 ± 9.6 (41–78)	64.4 ± 10.0	61.5 ± 9.2
Disease duration, y	15.0 ± 8.0 (3–40)	15.6 ± 7.5	14.3 ± 8.7
SARA score, points (Range, 0–40)	15.9 ± 7.1 (4–33)	18.2 ± 6.2	13.6 ± 7.3*
BI score, points (Range, 0–100)	77.4 ± 22.4 (15–100)	72.2 ± 23.0	82.6 ± 20.9
IDR-ICARS score, points (Range, 0–26)	14.8 ± 6.0 (5–26)	16.6 ± 5.6	13.1 ± 6.1*
IDR-BI score, points (Range, 0–55)	36.7 ± 15.1 (5–55)	33.5 ± 16.1	40.0 ± 13.7
CAG repeat length of the expanded CACNA1A allele^a	23.2 ± 1.4 (21–27)	23.2 ± 1.3	23.3 ± 1.6

Where applicable, the values are given as the mean ± standard deviation (range).
Abbreviations: BI = Barthel Index; CACNA1A = alpha 1A P/Q type voltage-dependent calcium channel gene; CAG = cytosine-adenine-guanine; ICARS = International Cooperative Ataxia Rating Scale; IDR = Intractable Diseases Research; SARA = Scale for the Assessment and Rating of Ataxia.
IDR-BI = total points of 6 items from the BI assessed by the IDR registry.
IDR-ICARS = total points of 5 items from the ICARS assessed by the IDR registry.
^aThree patients are homozygous for the expanded allele (repeat lengths: 20, 22, and 24). The mean ± standard deviation was applied for 43 patients heterozygous for the expanded allele (22 male and 21 female patients).
*The scores of female patients were significantly lower than those of male patients (P < .05, Mann–Whitney test).

ISSN: 1750-1172