Genetic Aspects of Succinylcholine Sensitivity

Investigations of the serum cholinesterase of individuals known to be excessively sensitive to succinylcholine have resulted in the recognition of many variants. These have been identified by the use of various esterase inhibitors of widely differing chemical structures. Subsequent family studies have shown that these variants are genetically determined by four allelic genes functioning at the same locus. More recent studies using sodium chloride, n-butyl alcohol and formaldehyde to inhibit serum cholinesterase differentially have indicated the probable existence of more phenotypes. These will have to be confirmed by family studies and more extensive screening of random populations. The existence of these new phenotypes may help to resolve the unexpectedly high proportion of succinylcholine-sensitive individuals typed as “normal” phenotype by established methods.