congenital myasthenic syndrome 4A

A congenital myasthenic syndrome characterized by postsynaptic neuromuscular junction defects, early-onset progressive muscle weakness, and prolonged opening and activity of the acetylcholine receptor channel that has_material_basis_in heterozygous or rarely b

A congenital myasthenic syndrome characterized by postsynaptic neuromuscular junction defects, early-onset progressive muscle weakness, and prolonged opening and activity of the acetylcholine receptor channel that has_material_basis_in heterozygous or rarely biallelic mutation in the CHRNE gene on chromosome 17p13.

Signs and symptoms

• EMG: decremental response of compound muscle action potential to repetitive nerve stimulation
• Type 2 muscle fiber atrophy
• Strabismus
• Sudden episodic apnea
• Fatigable weakness
• Myopathy
• Generalized hypotonia due to defect at the neuromuscular junction
• Generalized hypotonia
• Limb muscle weakness
• Feeding difficulties in infancy

Also known as: CMS Ia1; CMS1A1; CMS4A; congenital myasthenic syndrome 4A slow-channel; congenital myasthenic syndrometype Ia1