|
Phenotype
|
Motor and sensory neuropathy
|
Motor neuropathy
|
|
Origin
|
Korean (Asian)
|
Mali (African)
|
|
Mutation
|
Compound heterozygous missense
|
Homozygous missense
|
|
Nucleotide change
|
c.1988C > T, c.2458G > C
|
c.1940T > C
|
|
Amino acid change
|
p.Thr663Met, p.Gly820Arg
|
p.Phe647Ser
|
|
Age at onset
|
8 years
|
2–11.5 years
|
|
Symptom at onset
|
Distal muscle weakness of lower limbs
|
Proximal muscle weakness and early involvements of foot and hand
|
|
Muscle weakness
| | |
|
Upper limb, proximal
|
No
|
Yes
|
|
Upper limb, distal
|
Yes
|
Yes
|
|
Lower limb, proximal
|
Yes
|
Yes
|
|
Lower limb, distal
|
Yes
|
Yes
|
|
Muscle atrophy
|
Proximal < distal
|
Proximal = distal (generalized)
|
|
Sensory loss
|
Yes
|
No
|
|
Areflexia
|
Yes
|
Yes
|
|
Pyramidal sign
|
No
|
No
|
|
Bulbar symptom
|
No
|
No
|
|
Cranial neuropathy
|
No
|
No
|
|
Foot deformity
|
Yes
|
Yes
|
|
Scoliosis
|
No
|
Yes
|
|
Respiratory dysfunction
|
No
|
Yes (60%)
|
|
Wheelchair bound
|
No
|
Yes (80%)
|
|
Nerve conduction study
|
Sensorimotor neuropathy
|
Motor neuropathy
|
|
Electromyography
|
Muscle denervation
|
Muscle denervation
|
|
Sural nerve biopsy
|
Severe loss of myelinated fibers (297/mm2, normal: 9,800/mm2)
|
Normal
|
|
References
|
This study
|
Maystadt et al. (2006) [2]
|
