Clinical features
| Feature | Affected family member | ||||
|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | |
| The case numbers 1–5 correspond to the affected cases from left to right in fig 1 below. | |||||
| Findings are graded by relative severity: −absent; +mild; ++moderate; +++severe. | |||||
| IQ, Wechsler adult intelligence scale; LL, lower limb. | |||||
| Age at examination (years) | 42 | 39 | 36 | 30 | 22 |
| Onset | 6 years | 6 years | 6 years | 6 years | 11 years |
| Dysarthria | +++ | +++ | +++ | +++ | − |
| Tongue tremors | + | + | + | + | + |
| Atrophy of small hand muscles | +++ | + | +++ | +++ | +++ |
| Muscle tone | Spastic LL | Spastic LL | Spastic LL | Spastic LL | Slightly spastic LL |
| Knee reflex | +++ | +++ | +++ | +++ | − |
| Clonus | +++ | + | + | − | − |
| Extensor plantar response | +++ | +++ | +++ | − | − |
| Gait | Spastic ataxic | Spastic | Spastic | Spastic | Spastic |
| Emotional lability | + | +++ | + | +++ | |
| IQ | Total 55 | Total 61 | Total 54 | Total 56 | Total 68 |
| Verbal 55 | Verbal 55 | Verbal 52 | Verbal 48 | Verbal 73 | |
| Performance 61 | Performance 72 | Performance 73 | Performance 73 | Performance 64 | |