Table 1.
Clinical information of the affected individuals in the pedigree
| Clinical information | ||||||
|---|---|---|---|---|---|---|
| Features | IV.2 | IV.3 | IV.4 | IV.5 | V.1 | V.2 |
| Age | 30 | 28 | 25 | 22 | 12 | 9 |
| Gender | Female | Female | Male | Male | Male | Female |
| Developmental delay | ++ | ++ | ++ | ++ | ++ | ++ |
| Seizures | GTCS | GTCS | GTCS | GTCS | GTCS | GTCS |
| Ataxia | ++ | ++ | ++ | ++ | ++ | ++ |
| Nystagmus | Upgaze nystagmus | No | No | Horizontal gaze evoked | No | No |
| Incoordination | ++ | ++ | ++ | ++ | ++ | ++ |
| Muscle tone | Increased (spastic type) | Increased (spastic type) | Increased (spastic type) | Increased (spastic type) | Increased (spastic type) | Increased (spastic type) |
| DTRs | Exaggerated | Exaggerated | Exaggerated | Exaggerated | Exaggerated | Exaggerated |
| Plantar | Extensor | Extensor | Extensor | Extensor | Extensor | Extensor |
| Irritability | + | + | + | + | + | + |
| Stereotypes | − | − | + | − | + | − |
| Psychosis | + | − | − | − | − | − |
| Hyperactivity | − | − | + | − | + | + |
| Speech | Dysarthric (scanning + spastic) | Dysarthric (scanning + spastic) | Dysarthric (scanning + spastic) | Dysarthric (scanning + spastic) | No speech | No speech |
| Gait | Unable to walk | Unable to walk | Unable to walk | Unable to walk | Walks with support | Walks with support |
| Audiometry | Mild SNHL | Mild SNHL | Severe SNHL | Severe SNHL | Moderate SNHL | Moderate SNHL |
| IQ | Not done | Not done | Not done | Not done | Profound mental retardationa | Profound mental retardationa |
aIQ is measured using Vineland Social Maturity Scale (VSMS) and found to be < 20