| Phenotype details |
progressive disease; delayed motor development; motor neuropathy, sensory neuropathy; predominant demyelinating neuropathy, axonal neuropathy; absent vibration sense, reduced perception of touch; diminished biceps reflex, diminished patellar reflex, diminished achilles reflex; no spasticity; upper limb proximal muscle weakness; upper limb distal muscle weakness hand intrinsics; minimal lower limb distal muscle weakness; lower limb proximal muscle weakness; upper limb muscle atrophy distal, not proximal; lower limb muscle atrophy distal, not proximal; upper limb motor nerve distal motor latency prolonged, median 2.1 ms, ulnar 3.8–5.9 ms, nerve conductance velocity reduced, median 32–35 m/s, ulnar 25–27 m/s, compound muscle action potential reduced-normal, median 3.7–7.3 mv, ulnar: 0.8–1.4 mv; upper limb sensory nerve no response; lower limb motor nerve distal motor latency prolonged, tibial no response, peroneal 9.2–44 ms, nerve conductance velocity tibial no respeonse, peroneal normal 90 m/s, compound muscle action potential reduced, tibial no response, peroneal 0.2–2.3 mv; lower limb sensory nerve no response; MRI brain normal, MRI spine normal; no seizures, EEG sleep bursts of generalised spine and polyspike and wave discharges; no intellectual disability; no dysmorphism; scoliosis, hand and foot deformities |
