Subject | II.2 | II.1 | I.2 |
---|---|---|---|
Gender | m | f | f |
Phenotypic cluster | CMTX5/Arts | DFN2 | None |
Current age | 36 | 42 | 66 |
Age of onset first symptom | Congenital, hearing loss | Congenital, hearing loss | None |
Neurological | |||
Mental retardation | (+) progressive aggressive, childish behavior, starting at age 18 | - | - |
Ataxia (age of onset) | +, 30 years | - | - |
Severity of ataxia (SARA score) | 14 out of 40 | 1 out of 40 | 0 out of 40 |
Delayed motor development | - | - | - |
Loss of deep tendon reflexes | + | - | - |
Hearing loss (age of onset) | +, congenital | +, congenital | |
Optic atrophy (age of onset) | 12 | -- | - |
Uric acid overproduction | |||
Gout | - | - | - |
Kidney stones | - | - | - |
Renal failure | - | - | - |
Serum uric acid (ref 3.4-7.0 mg/dl) | 4.3 mg/dl | 4.4 mg/dl | 4.2 mg/dl |
Hematopoetic | |||
Recurrent infections | (+), only from age 6 to 8 years | - | - |
Anemia | - | - | - |
Other | |||
Short stature | - | - | - |
Self-injury | - | - | - |
Early death | - | - | - |
Lab, electrophysiology and MRI investigations | |||
Nerve conduction studies | |||
-Sensory nerve conduction | Sur: no SNAP; Rad: no SNAP | Sur: normal, Rad: normal | n.d. |
Sural or radial nerve | |||
-Motor nerve conduction | Tib: borderline MNCV (40 m/s; ref > 40 m/s); Uln: reduced CMAP (2.1 mV; ref: > 4 mV); reduced MNCV (36 m/s; ref: > 50 m/s) | Tib: normal; Uln: normal | |
Tibial or ulnar nerve | |||
MRI | Mild cerebellar and parietal cortical atrophy | Mild cerebellar and parietal cortical atrophy | n.d. |
Serum creatinkinase (ref <180 U/l) | 1168 U/l | 141U/l | 196 U/l |
PRS-I enzyme activity (ref 0.41-1.46 nmol/(min.mg protein) | <0.005 nmol/(min.mg protein) | 0.1 nmol/(min.mg protein) | 1.04 nmol/(min.mg protein) |