TABLE 1.
Demographics and main diagnostic features of SCA21 patients
| Family | A | B | C | D | |
|---|---|---|---|---|---|
| Patient | I‐1 | II‐2 | II‐3 | II‐4 | II‐5 |
| Sex | M | M | M | M | M |
| Origin | Libya | Libya | Italy | Italy | Italy |
| Age of onset, years | 62 | 40 | 30 | 3 | 0 |
| Age at diagnosis, years | 79 | 46 | 52 | 12 | 7 |
| Symptom of onset | GA | GA | GA | Clumsiness | DD |
| Gait ataxia | +++ | + | ++ | ++ | ++ |
| Dysarthria | ++ | + | – | – | – |
| Hypokinetic signs | – | – | – | – | – |
| Hyperkinetic signs | – | – | – | – | +(DY) |
| Ocular findings | Ny | Ny | HS | HS | OP |
| Tremor | – | + (postural) | + (postural) | + (intention) | + (intention and postural) |
| Psychomotor delay | – | – | – | + | ++ |
| Cognitive decline | ++ | + | + | – | – |
| SARA at first visit | 15 | 6.5 | 10 | 5 | n.d. |
| SARA at last visit | 18 | 6.5 | 23 | 6 | n.d. |
| Timespan of FU | 4 years | – | 7 years | 7 years | 6 years |
| Progression rate | 0.6/year | – | 0.8/year | 0.16/year | – |
| Neuroimaging | CA | n.d. | CA | CA | DM |
| Behaviour disorder | – | – | – | + | ++ |
| Others | – | REM‐BD | Strabismus | Hearing loss | – |
| Mutation |
c.509C>T p.Pro170Leu |
c.509C>T p.Pro170Leu |
c.509C>T p.Pro170Leu |
c.239C>T p.Thr80Met |
c.196G>A p.Gly66Arg |
Abbreviations: –, not present; +, mild; ++, moderate; +++, severe; CA, cerebellar atrophy; DY, dystonia; FU, follow‐up; GA, gait ataxia; HS, hypermetric saccades; ID, developmental delay; M, male; n.d., not determined; Ny, nystagmus; OP, Opsoclonus; REM‐BD, REM sleep‐behavior disorder; SARA, Scale for the Assessment and Rating of Ataxia.