A family segregating for E1j and E1k at cholinesterase locus 1.

A family segregating for the A, J, and K alleles at cholinesterase locus 1 is described. Several further examples of the AJ and AK phenotypes occur in this family, and one member of the family, by genetic analysis, is phenotype JK. In relation to possible succinylcholine apnoea, phenotypes AJ, AK, and JK should all be considered vulnerable.