congenital myasthenic syndrome 4C

A congenital myasthenic syndrome characterized by autosomal recessive inheritance of postsynaptic neuromuscular junction defects, early-onset muscle weakness, and low amplitude of the miniature endplate potential and current that has_material_basis_in homozygo

A congenital myasthenic syndrome characterized by autosomal recessive inheritance of postsynaptic neuromuscular junction defects, early-onset muscle weakness, and low amplitude of the miniature endplate potential and current that has_material_basis_in homozygous or compound heterozygous mutation in the CHRNE gene on chromosome 17p13.

Signs and symptoms

• Fatigable weakness
• Ophthalmoparesis
• EMG: decremental response of compound muscle action potential to repetitive nerve stimulation
• Ptosis
• Type 2 muscle fiber atrophy
• Facial palsy
• Strabismus
• Decreased muscle mass
• Hypotonia
• Muscle spasm

Also known as: CMS Id; CMS1D; CMS4C; FIM1; congenital myasthenic syndrome 4C associated with acetylcholine receptor deficiency