Frequencies of Pseudocholinesterase Variants in Icelanders, Greeks and Pakistanis

Abstract

THE formation of the human pseudocholinesterase variants is controlled by at least four alleles at one autosomal locus termed E₁ (ref. 1). The four alleles are $E_{1^u}$, $E_{1^a}$, $E_{1^f}$ and $E_{1^s}$ (refs. 2–5). The heterozygotes $E_{1^u}$ $E_{1^a}$ have been found in remarkably uniform frequencies, about 3 to 6 per cent, in Caucasians from Europe and North America^3,8–11, and also in Australian aborigines¹² and Mexican Indians¹³, but are relatively rare among Negroes¹¹ and Mongoloids^10,11,14.