Recognition of the E1kE1f cholinesterase genotype in a family segregating three rare genes, E1k, E1f and E1a.

The first identification of the cholinesterase variant E1kE1f is reported from a family study. The evidence is based on the determination of enzymic activity, dibucaine, fluoride and RO2 numbers. Three individuals appear to have this genotype, and family evidence is not at variance with our conclusions. All three individuals will be sensitive to suxamethonium.