congenital myasthenic syndrome 1B

info · Genetic

A congenital myasthenic syndrome characterized by defects in postsynaptic neuromuscular junctions with early-onset progressive muscle weakness that has_material_basis_in mutation in the CHRNA1 gene on chromosome 2q.

Signs and symptoms

Limb muscle weakness
Weakness of facial musculature
EMG: decremental response of compound muscle action potential to repetitive nerve stimulation
Easy fatigability
Neck muscle weakness
Type 2 muscle fiber atrophy
Facial palsy
Hypotonia
Motor delay
Gowers sign

Also known as: CMS1B; congenital myasthenic syndrome 1B, fast-channel