Table 1 Clinical comparison of all reported patients carrying PMP2 mutations
From: Peripheral myelin protein 2 – a novel cluster of mutations causing Charcot-Marie-Tooth neuropathy
Patient | A.III-1 | A.II-2 | B.II-2 | B.II-1 | Hong YB et al. | Motley W et al. 2016 | Gonzaga-Jauregui et al. 2015 | Punetha J et al. 2018 | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
II-4 | III-1 | III-3 | Family I/II.3 | Family I/III.2 | Family II/II.3.1 | Family II/IV.5 | Family II/IV.1 | |||||||
Mutation in PMP2 | p.M114 T | p.M114 T | p.V115A | p.V115A | p.I43N | p.I43N | p.I43N | p.I52T | p.I52T | p.T51P | p.T51P | p.T51P | p.I43N | p.I52T |
Sex | F | M | M | M | F | M | M | M | M | F | F | F | M | F |
Age at onset | 1.5 y | 1 y | 2–3 y | 2–3 y | 18 y | 6 y | 8 y | 17 y | 3 y | 5 y | NR | 18 mo | 6 | 5 |
First symptoms | Delay in starting to walk, frequent falls | Walking with frequent falls | Slight clumsiness during physical activities | Slight clumsiness foot deformity | Distal leg muscle weakness | Frequent falling | Distal leg muscle weakness | Foot drop, frequent falling | Impaired coordination, frequent falling | Distal leg muscle weakness | Distal leg muscle weakness | Delay in starting to walk | NR | Distal leg muscle weakness |
Age of involvement of upper limbs | 29 y | 34 y | 40 y | 40 y | 41 y | 20 y | 28 y | NR | No involvement | NR | NR | No involvement | NR | NR |
Age at last examination | 37 y | 34 y | 44 y | 45 y | 58 y | 38 y | 36 y | 48 y | 13 y | 37 y | 13 y | 24 y | NR | 21 |
WEAKNESS: LOWER LIMBS (MRC SCALE) | ||||||||||||||
Knee flexion/extension | 4/5 | 4/5 | 5/5 | 5/5 | NR | NE | NE | 5/5 | 5/5 | NR | NR | 5/5 | NR | NR |
Foot dorsiflexion | 1/5 | 2/5 | 4/5 | 5/5 | 4/5 | < 4/5 | 4/5 | 4−/5 | 3/5 | 0/5 | NR | 1/5 | NR | NR |
Plantar flexion | 3/5 | 3/5 | 4/5 | 5/5 | NR | NR | NR | 5/5 | 5/5 | 0/5 | NR | 4/5 | NR | NR |
Great toe extension | 0/5 | 1/5 | 4/5 | 5/5 | NR | NR | NR | 0/5 | 3/5 | 0/5 | NR | 0/5 | NR | NR |
WEAKNESS: UPPER LIMBS (MRC SCALE) | ||||||||||||||
Elbow flexion/extension | 5/5 | 5/5 | 5/5 | 5/5 | NR | NR | NR | 5/5 | 5/5 | NR | NR | 5/5 | NR | NR |
Wrist flexion | 4/5 | 5/5 | 5/5 | 5/5 | NR | NR | NR | 5/5 | 5/5 | NR | NR | 5/5 | NR | NR |
Wrist extension | 4/5 | 5/5 | 5/5 | 5/5 | NR | NR | NR | 5/5 | 5/5 | NR | NR | 5/5 | NR | NR |
Finger flexion | 3+/5 | 45 | 5/5 | 5/5 | 4/5 | NR | < 4/5 | 5/5 | 5/5 | NR | 4/5 | 3–4/5 | NR | NR |
Finger extension | 4/5 | 4/5 | 5/5 | 5/5 | 4/5 | NR | < 4/5 | 5/5 | 5/5 | NR | 4/5 | 3–4/5 | NR | NR |
Thumb abduction | 3/5 | 4/5 | 5/5 | 5/5 | NR | NR | NR | 4−/5 | 5/5 | More affected than the other intrinsic hand muscles | 4/5 | 1/5 | NR | NR |
REFLEXES | ||||||||||||||
Brachioradial | – | +/− | – | +/− | NR | NR | NR | NR | +/− | +/− | + | – | – | – |
Biceps | +/− | +/− | – | – | NR | NR | NR | – | +/− | +/− | + | – | – | – |
Triceps | +/− | +/− | – | – | NR | NR | NR | NR | +/− | +/− | + | – | – | – |
Patellar | – | – | – | – | – | – | +/− | – | – | – | – | – | – | – |
Achille | – | – | – | – | – | – | +/− | – | – | – | – | – | – | – |
SENSATION MODALITIES: LOWER LIMBS | ||||||||||||||
Superficial | D | D | N | N | D | D | D | D | D | D | N | D | D | NR |
Vibration | D | D | N | N | D | D | D | D | D | NR | N | D | D | NR |
Romberg sign | + | + | NE | NE | NR | NR | NR | NR | NR | NR | N | + | NR | NR |
SENSATION MODALITIES: UPPER LIMBS | ||||||||||||||
Superficial | N | N | N | N | D | D | D | N | N | NR | N | D | D | NR |
Vibration | N | N | N | N | D | D | D | N | N | NR | N | D | D | NR |
Independent ambulation | Preserved/steppage | Preserved/steppage | Preserved | Preserved | Preserved | Preserved | Preserved | Preserved | Preserved | Preserved with difficulties | Preserved | Preserved | NR | Preserved/steppage |
Walking aids used | No | No | Orthopedic shoes | No | Ankle-foot orthoses | Ankle-foot orthoses | Ankle-foot orthoses | Ankle foot orthoses | NR | NR | NR | NR | NR | No |
Skeletal deformities | Pes cavus and equinovarus | Pes cavus and equinovarus | Pes varus L > R | Pes varus | Pes cavus | Pes cavus | Pes cavus | NR | Pes cavus | Pes cavus and equinovarus | Pes equinovarus | Pes equinovarus | Pes cavus, | Pes cavus at the age of 12 y Pes planus at the age of 20 y |
Foot deformity surgery | No | Yes, at the age of 26 y | On the left foot at the age of 41 y | No | NR | No | Achilles tendon lengthening Surgery at the age of 11 | NR | At the age of 11 y | NR | Two on the right foot | |||
Muscle atrophy | Severe for calf, peroneal, foot muscles and milder for thenar and hypothenar muscles | Moderate for calf, peroneal, foot muscles | Mild for calf, peroneal, foot muscles | No | Mild (U < L) | Moderate (U < L) | Mild (U < L) | NR | Atrophy of calf, peroneal, foot muscles | Atrophy of calf, peroneal, foot, intrinsic hand muscles | Atrophy of calf, peroneal, and foot muscles | Atrophy of calf, peroneal, and foot muscles | Atrophy of calf, peroneal, foot, intrinsic hand muscles | NR |
CMT neuropathy score | 15 | NE | NE | NE | 9 | 20 | 13 | 14 | 12 | NR | NR | NR | NR | NR |
9HPT | 25.7 s | NE | NE | NE | 22.7 s | 31.4 s | 26.3 s | NR | NR | NR | NR | NR | NR | NR |
Any additional features | No | No | No | Epilepsy with generalized seizures since adolescence | Hand tremor | Hand tremor | Hand tremor | No | No | No | No | No | No | NR |
Muscle MRI findings | Predominant signal changes in the anterior and lateral compartments of the lower leg muscles | NE | NE | NE | Predominant signal changes in the anterior and lateral compartments of the lower leg muscles | Predominant signal changes in the anterior and lateral compartments of the lower leg muscles | Predominant signal changes in the anterior and lateral compartments of the lower leg muscles | NE | NE | NE | NE | NE | NE | NE |
Sural nerve biopsy | NE | NE | NE | NE | Onion bulbs and degenerating fibers with various myelin abnormalities | NE | NE | Onion bulbs, reduced density of myelinated axons | NE | NE | NE | NE | Demyelinating neuropathy; onion bulb formation | NE |