Table 1.
Demographics, clinical characteristics, and number of CAG repeats for patients with SCA in the current study
| CAG repeat range | SCA1 (n = 5) | SCA2 (n = 33) | SCA3 (n = 48) | SCA6 (n = 1) | SCA17 (n = 3) | ||||
|---|---|---|---|---|---|---|---|---|---|
|
Pathological repeat number (n = 3) |
Intermediate repeat number (n = 2) |
Pathological repeat number (n = 27) |
Intermediate repeat number (n = 6) |
Pathological repeat number (n = 43) |
Intermediate repeat number (n = 1) |
Combined borderline repeats in SCA2a (n = 4) |
Pathological repeat number (n = 1) |
Intermediate repeat number (n = 3) |
|
| No. of repeats | 49.0 ± 1.7 (N ≤ 35, P ≥ 39) | 36.5 ± 0.7 | 38.0 ± 4.1 (N ≤ 23, P ≥ 33) | 25.7 ± 1.2 | 69.8 ± 4.1 (N ≤ 36, P ≥ 52) | 45 | 21 (N ≤ 18, P ≥ 20) | 41.7 ± 0.6 (N ≤ 40, P ≥ 49) | |
| Age of onset, years | 41.0 ± 2.6 | 41.0 ± 14.1 | 37.6 ± 13.5 | 49.3 ± 11.0 | 42.6 ± 17.2 | 53 | 39.0 ± 4.8 | 62 | 53.0 ± 8.5 |
| Age of examination, years | 45.7 ± 4.0 | 43.5 ± 10.6 | 42.9 ± 14.2 | 46.7 ± 19.8 | 46.2 ± 15.5 | 54 | 42.3 ± 6.8 | 64 | 46.0 ± 16.4 |
| Male | 2 (66.7%) | 0 | 17 (62.9%) | 3 (100%) | 16 (37.2%) | 1 (100%) | 1 (33.3%) | 1 (100%) | 2 (66.7%) |
| Positive family history | 3 (100%) | 1 (50%) | 23 (85.2%) | 2 (33.3%) | 34 (79.1%) | N.A. | 2 (50%) | 1 (100%) | 1 (33.3%) |
| Clinical features | |||||||||
| Ataxia | 3/3 (100%) | 2/2 (100%) | 23/24 (95.8%) | 3/3 (100%) | 37/38 (97.4%) | 1/1 (100%) | 3/4 (75%) | 1/1 (100%) | 2/2 (100%) |
| Parkinsonism | 0 | 1/2 (50%) | 4/24 (16.7%) | 2/3 (66.7%) | 5/38 (13.2%) | 1/1 (100%) | 4/4 (100%) | 0 | 2/2 (100%) |
| Tremor pred. | N.A. | 1/1 (100%) | 1/4 (25%) | 1/2 (50%) | 1/5 (20%) | 1/1 (100%) | 3/4 (75%) | N.A. | N.A. |
| Akinetic‐rigidity | N.A. | N.A. | 3/4 (75%) | 1/2 (50%) | 4/5 (80%) | N.A. | 1/4 (25%) | N.A. | 2/2 (100%) |
| Good levodopa response | N.A. | N.A. | 3/4 (75%) | 0 | 2/5 (40%) | 0 | 4/4 (100%) | N.A. | 0 |
| Dystonia | 0 | 0 | 1/24 (4.2%) | 1/3 (33.3%) | 1/38 (2.6%) | 0 | 1/4 (25%) | 0 | 0 |
| Chorea | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Polyneuropathy | 0 | 0 | 8/24 (66.7%) | 1/3 (33.3%) | 14/38 (36.8%) | 0 | 2/4 (50%) | 0 | 1/2 (50%) |
| Pyramidal signs | 1/3 (33.3%) | 1/2 (50%) | 5/24 (20.8%) | 1/3 (33.3%) | 6/38 (15.8%) | 0 | 2/4 (50%) | 0 | 0 |
| Slow saccade | 1/3 (33.3%) | 0 | 14/24 (58.3%) | 2/3 (66.7%) | 11/38 (28.9%) | 0 | 0 | 0 | 1/2 (50%) |
| Ophthalmoplegia | 0 | 0 | 0 | 0 | 4/38 (10.5%) | 0 | 0 | 0 | 0 |
| Nystagmus | 0 | 0 | 2/24 (8.3%) | 0 | 19/38 (50%) | 0 | 2/4 (50%) | 0 | 1/2 (50%) |
| Cognitive impairment | 0 | 0 | 1/24 (4.2%) | 1/3 (33.3%) | 4/38 (10.5%) | 0 | 0 | 0 | 1/2 (50%) |
| Psychiatric symptoms | 0 | 1/2 (50%) | 2/24 (8.3%) | 1/3 (33.3%) | 3/38 (7.9%) | 0 | 2/4 (50%) | 0 | 1/2 (50%) |
| Seizure | 0 | 1/2 (50%) | 0 | 0 | 1/38 (2.6%)b | 0 | 0 | 0 | 0 |
| mRS at genetic study | 1.7 ± 0.6 | 1.5 ± 0.7 | 1.8 ± 1.3 | 1.2 ± 1.6 | 1.7 ± 1.0 | 1.0 | 2.0 ± 1.4 | 2.0 | 2.0 ± 2.0 |
| Follow‐up duration, months | 18.1 ± 10.1 | 52.3 ± 63.1 | 31.3 ± 35.9 | 41.3 ± 37.5 | 29.9 ± 36.8 | 19.5 | 69.9 ± 49.6 | 16.9 | 17.3 ± 11.1 |
| mRS at last follow‐up | 2.0 ± 0.0 | 5.0 ± 1.4 | 2.4 ± 1.3 | 1.8 ± 2.2 | 2.3 ± 1.4 | 4.0 | 2.3 ± 1.3 | 2.0 | 2.7 ± 3.1 |
| Received SSR/RRIV | 0 | 0 | 2 (7.4%) | 2 (33.3%) | 8 (18.6%) | 1 | 3 (75%) | 0 | 1 (33.3%) |
| Normal | N.A. | N.A. | 1 (50%) | N.A. | 3 (37.5%) | 1 | 3 (100%) | N.A. | N.A. |
| Abnormal | N.A. | N.A. | 1 (50%) | 2 (100%) | 5 (62.5%) | N.A. | N.A. | N.A. | 1 (100%) |
Abbreviations: mRS, modified Rankin Scale; N, normal repeat number; N.A., not applicable; P, pathological repeat number; Pred. predominant; RRIV, R‐R interval variability; SCA, spinocerebellar atrophy; SSR, sympathetic skin response.
Patients with pathological CAG repeats in the ATXN3 gene (no. of repeats 67.5 ± 2.6) and intermediate increased CAG repeats in the ATXN2 gene (no. of repeats 26.5 ± 1.7).
The patient had post‐traumatic epilepsy.