Sex and population differences in the incidence of a plasma cholinesterase variant.

Accumulating knowledge of polymorphic enzyme systems poses intriguing possibilities of anthropologic genetics. Development of an automated procedure for determination of heterozygosity or homozygosity of the atypical plasma cholinesterase allele (E(1)(a)) permitted screening of 2317 individuals during a national Preschool Nutrition Survey and several smaller population studies. Frequencies of the allele (E(1)(a)) closely parallel those previously reported. Caucasians manifested a heterozygote male preponderance of 1.85: 1.