Clinical and electrophysiological features in CMT2 patients of FC162 family
| Phenotypes/patients (sex) | II-3 (female) | III-2 (male) |
|---|---|---|
| Age at onset/examination (years) | 13/42 | 3/8 |
| Muscle weakness in limb (upper/lower) |
++/+++ | +/+++ |
| Muscle atrophy | Moderate | Mild |
| Foot deformities | Yes | Yes |
| Pinprick sense in limb (upper/lower) | Reduced/reduced | Mildly reduced/reduced |
| Vibration in limb (upper/lower) | Reduced/reduced | Mildly reduced/reduced |
| Deep tendon reflex (knee and ankle jerk) | Absent | Absent |
| Scoliosis | Yes | Yes |
| Pyramidal sign | No | No |
| Brainstem auditory evoked potential | Not done | Normal |
| FDS | 3 (walking difficulty) | 3 (walking difficulty) |
| CMTNSv2/CMTNSv2-R | 17 (moderate)/22 (severe) | 13 (moderate)/18 (moderate) |
| CMTES/CMTES-R | 15 (severe)/19 (severe) | 12 (moderate)/16 (moderate) |
| Motor nerve conduction |
||
| Median CMAP (mV)/MNCV (m/s) | 13.5/42.5 | 11.8/46.3 |
| Peroneal CMAP (mV)/MNCV (m/s) | Absent/absent | Absent/absent |
| Sensory nerve conduction |
||
| Ulnar SNAP (μV)/SNCV (m/s) | 7.2/28.2 | 12.9/29.8 |
| Sural SNAP (μV)/SNCV (m/s) | Absent/absent | Absent/absent |
CMAP, compound muscle action potential; CMTES, CMT examination score; CMTES-R, Rasch-modified CMTES; CMTNSv2, CMT neuropathy score version 2; CMTNSv2-R, Rasch-modified CMTNSv2; FDS, functional disability scale; MNCV, motor nerve conduction velocity; SNAP, sensory nerve action potential; SNCV, sensory nerve conduction velocity.
aUpper limb: + and ++ = intrinsic hand weakness 4/5 and < 4/5 on the MRC scale. Lower limb: + and ++ = ankle dorsiflexion 4/5 and < 4/5 on the MRC scale; +++ = proximal weakness.
bNormal voltages of motor median nerve ≥6 mV, peroneal nerve ≥1.6 mV, sensory ulnar nerve ≥7.9 μV, and sural nerve ≥6.0 μV; normal conduction velocities of motor median nerve ≥50.5 m/s, peroneal nerve ≥41.2 m/s, sensory ulnar nerve ≥37.5 m/s and sural nerve ≥32.1 m/s.