Table 1 Electrophysiological features of patients with the c.179+1G→C mutation.
| Motor nerve conduction velocities | Sensory nerve conduction velocities | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Median | Peroneal | Median | Sural | |||||||||
| DL (ms) (<4) | CMAP (mV) (>7) | MCV (m/s) (>50) | DL (ms) (<5) | CMAP (mV) (>5) | MCV (m/s) (>40) | DL (ms) | SAP (mV)(>14) | SCV (m/s)(>44) | DL (ms) | SAP (mV) (>4) | SCV (m/s) (>40) | |
| II.1 | 4.78* | 8.74 | 51.1 | 7.75* | 2.12* | 37.2* | 4.85 | 12 | 29.9* | 4.73 | 12.9 | 36.5* |
| II.3 | 6.87* | 7.45 | 54.7 | 7.35* | 3.34 | 42.6 | 4.5 | 10.4 | 30.2* | 4.19* | 14.8 | 33.4* |
| I.2 | 6.22* | 7.32 | 60.8 | 7.25* | 3.56* | 33.3* | 4.55 | 4.69* | 23.9* | 4.41* | 3.97 | 31.7* |
Normal reference values in brackets.
*Pathological values.
CMAP, compound muscle action potential amplitude (mV); DL, distal latencies; MCV, motor conduction velocity (m/s); SAP, sensory action potential (μV); SCV, sensory conduction velocity (m/s).