Figure 5. Congenital myasthenic syndrome mutations in the receptor.

Amino acids identified in human fast- or slow-channel syndromes are shown as spheres mapped onto the Torpedo structure. Point mutations in the human muscle nicotinic receptor causing myasthenia are found predominantly on α₁ and ε subunits. The majority of the residues at these positions are conserved in the Torpedo receptor α and γ subunits, respectively (α₁/α: 80% and ε/γ: 56% amino acid sequence identity).