Background
Methods
Subjects
Clinical assessments
Electrophysiological study
Sural nerve biopsy
Vastus lateralis muscle biopsy
MR images of brain, hip, thigh and lower leg
Exome sequencing and filtering
Construction of wild-type and mutant MPV17
Transfection and knockdown of MPV17
Measurement of proliferation and cell viability
Western blotting
Results
Identification of a novel homozygous mutation in MPV17 gene
Clinical manifestations
Patient 1
Patient 2
Sensory nerve involvement in the early stage of disease
Patient 1 | Patient 2 | Normal value | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Age at exam (years) | 12 | 13 | 17 | 33 | 34 | 21 | 22 | |||||
Side | Rt | Rt | Rt | Rt | Lt | Rt | Lt | Rt | Lt | Rt | Lt | |
Median nerve | ||||||||||||
TL (ms) | 3.7 |
4.3
|
4.6
|
9.2
|
7.0
|
9.2
|
6.5
| 3.6 | 3.7 | 3.2 | 3.1 | <3.9 |
CMAP (mV) | 10.0 | 7.7 |
2.3
|
2.1
|
1.0
|
2.5
|
1.1
| 15.1 | 13.3 | 13.9 | 10.9 | >6.0 |
MNCV (m/s) |
39.6
|
41.3
|
57.1
|
39.0
|
38.6
|
41.1
|
41.5
| 59.5 | 57.1 | 61.3 | 54.4 | >50.5 |
Ulnar nerve | ||||||||||||
TL (ms) |
3.3
|
3.4
|
3.2
|
9.9
|
6.4
|
9.2
|
6.0
| 2.3 | 2.3 | 2.5 | 2.3 | <3.0 |
CMAP (mV) | 11.0 | 9.5 |
6.3
|
0.8
|
3.8
|
0.7
|
3.0
| 12.7 | 10.1 | 11.1 | 9.3 | >8.0 |
MNCV (m/s) | 51.7 |
43.5
|
39.0
|
43.4
|
39.0
|
43.5
|
40.4
| 56.1 | 62.6 | 56.9 | 60.5 | >51.1 |
Peroneal nerve | ||||||||||||
TL (ms) |
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
| <5.3 |
CMAP (mV) |
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
| >1.6 |
MNCV (m/s) |
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
| >41.2 |
Tibial nerve | ||||||||||||
TL (ms) |
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
| <5.4 |
CMAP (mV) |
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
| >6.0 |
MNCV (m/s) |
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
| >41.1 |
Median sensory nerve | ||||||||||||
SNAP (μV) |
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
| >8.8 |
SNCV (m/s) |
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
| >39.3 |
Ulnar sensory nerve | ||||||||||||
SNAP (μV) |
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
| >7.9 |
SNCV (m/s) |
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
| >37.5 |
Sural nerve | ||||||||||||
SNAP (μV) |
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
| >6.0 |
SNCV (m/s) |
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
| >32.1 |
H-reflex (ms) |
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
|
A
| <30.2 |