congenital myasthenic syndrome 4B

A congenital myasthenic syndrome characterized by autosomal recessive inheritance of postsynaptic neuromuscular junction defects, early-onset progressive muscle weakness, and kinetic abnormalities of the AChR channel that has_material_basis_in homozygous or co

A congenital myasthenic syndrome characterized by autosomal recessive inheritance of postsynaptic neuromuscular junction defects, early-onset progressive muscle weakness, and kinetic abnormalities of the AChR channel that has_material_basis_in homozygous or compound heterozygous mutation in the CHRNE gene on chromosome 17p13.

Signs and symptoms

• Weakness of facial musculature
• Ophthalmoplegia
• Fatigable weakness of skeletal muscles
• EMG: decremental response of compound muscle action potential to repetitive nerve stimulation
• Easy fatigability
• Feeding difficulties
• Hypotonia
• Respiratory insufficiency
• Ptosis
• Neonatal hypotonia

Also known as: CMS4B; congenital myasthenic syndrome 4B fast-channel