Table 1.
Clinical, electrophysiological, and molecular genetic characteristics of the sibling patients from family 1, 2, 3, and 4.
| Findings | Family 1 patient II.1 | Family 1 patient II.2 | Family 1 patient II.3 | Family 2 patient II.1 | Family 2 patient II.3 | Family 2 patient II.4 | Family 3 patient II.1 | Family 3 patient II.2 | Family 4 patient II.3 |
|---|---|---|---|---|---|---|---|---|---|
| Age/Gender | 18 years†/Male | 18 years/Female | 12 years/Male | 29 years/Female | 26 years/Female | 24 years/Male | 20 years/Male | 18 years/Female | 5 years/Female |
| Age of symptom onset | 4 years | 4 years | 4 years | 7 years | 1.5 years | 6 years | 4 years | 5 years | First months of life |
| Growth development | Height and Weight <3rd percentile | Height and Weight <3rd percentile | Height and Weight <3rd percentile | Height and Weight <3rd percentile | Height and Weight <3rd percentile | Height and weight normal | Height and Weight <3rd percentile | Height and Weight <3rd percentile | Not elicited |
| Muscles strength (MRC grade) | Upper limbs: 3/5 in proximal, and 2/5 in distal Lower limbs: 0/5 in proximal and distal |
Upper limbs: 4/5 in proximal, and 3/5 in distal Lower limbs: 4/5 in proximal, and 3/5 in distal |
Upper limbs: 5/5 in proximal, and 4/5 in distal Lower limbs: 5/5 in proximal; 4/5 in the left distal, and 3/5 in the right distal |
Upper limbs: 5/5 in proximal, and 4/5 in distal Lower limbs: 5/5 in proximal; 4/5 in the left distal, and 3/5 in the right distal |
Upper limbs: 4/5 in proximal, and 0/5 in distal Lower limbs: 0/5 in proximal; 0/5 in distal |
Upper limbs: 5/5 in proximal, and 5/5 in distal Lower limbs: 5/5 in proximal; 2/5 in distal |
Not elicited | Not elicited | Not elicited |
| DTRs | Absent | Absent | Absent | Absent | Absent | Absent | Absent | Absent | Absent |
| Gait | Wheelchair-bound at age 17 | Wheelchair-bound at age 18 | Walk without support | Wheelchair-bound at age 15 | Wheelchair-bound at age 15 | Walk without support | Steppage gait | Wheelchair-bound | Walk without support |
| Electrophysical findings | |||||||||
| Ulnar MAP at wrist (m/V) | Not elicited | Not elicited | 1.1 | Absent response | Absent response | Absent response | Not elicited | Not elicited | Not elicited |
| Ulnar MCV at wrist (m/s) | Not elicited | Not elicited | 8.15 | Absent response | Absent response | Absent response | Not elicited | Not elicited | Not elicited |
| Ulnar SNAP at wrist (μV) | Absent response | Absent response | Absent response | 9.6 (norm>15) | Absent response | Absent response | Not elicited | Not elicited | Not elicited |
| Ulnar SCV at wrist (m/s) | Absent response | Absent response | Absent response | 34 (norm>38) | Absent response | Absent response | Not elicited | Not elicited | Not elicited |
| Ulnar MAP below elbow (m/V) | Not elicited | Not elicited | 0.6 | Absent response | Absent response | Absent response | Not elicited | Not elicited | Not elicited |
| Ulnar MCV below elbow (m/s) | Not elicited | Not elicited | 20.2 | Absent response | Absent response | Absent response | Not elicited | Not elicited | Not elicited |
| Ulnar SNAP below elbow (μV) | Absent response | Absent response | Absent response | 8.5 (norm>10) | Absent response | Absent response | Not elicited | Not elicited | Not elicited |
| Ulnar SCV below elbow (m/s) | Absent response | Absent response | Absent response | 33 (norm>39) | Absent response | Absent response | Not elicited | Not elicited | Not elicited |
| Tibial MAP (mV) | Not elicited | Not elicited | 1.2 | Not elicited | Not elicited | Not elicited | Not elicited | Not elicited | Not elicited |
| Tibial MCV (m/s) | Not elicited | Not elicited | 8.95 | Not elicited | Not elicited | Not elicited | Not elicited | Not elicited | Not elicited |
| Tibial SNAP (μV) | Absent response | Absent response | Absent response | Not elicited | Not elicited | Not elicited | Not elicited | Not elicited | Not elicited |
| Tibial SCV (m/s) | Absent response | Absent response | Absent response | Not elicited | Not elicited | Not elicited | Not elicited | Not elicited | Not elicited |
†
Passed away; DL, distal latency; DTR, deep tendon reflex; MAP, compound muscle action potential; MCV, motor conduction velocity; MRC, Medical Research Council Grades for Muscle Strength; SNAP, sensory nerve action potential; SCV, sensory conduction velocity.