Cholinesterase variants in a South African population.

Results of cholinesterase studies in 56 white and 22 black patients in Bloemfontein hospitals who developed suxamethonium apnoea between March 1974 and April 1985 are reported. Genotypes of patients and families are compared with figures for the UK and Denmark. A higher incidence of the silent cholinesterase allele is confirmed; the incidence of other variants is similar. Black patients were found to be only of the silent genotype.