Recognition of Two New Phenotypes Segregating the E₁^k Allele for Plasma Cholinesterase

Abstract

The first identification of the cholinesterase variants E₁^kE₁^k and E₁^kE₁^s is reported from a family study. The evidence is based on the biochemical parameters of enzymic activity, and dibucaine, fluoride and R02 numbers. Two individuals appear to be homozygotes E₁^kE₁^k and two are heterozygotes E₁^kE₁^s with family evidence supportive of these genotypes. The heterozygotes E ₁^kE₁^s will be sensitive to suxamethonium.

Family Studies of the E₁^kE₁^s Genotype for Plasma Cholinesterase

“…The frequency of the gene in Cau casians has been reported [Evans and Warded, 1984] and confirmed by family studies [Whittaker and Britten, 1985], The recognition of the genotype E|kEjs segre gating in a large pedigree has recently been reported [Whittaker and Britten, 1988] and we supplement these data with three additional families segregating the genotype.…”

The butyrylcholinesterase K variant and susceptibility to Alzheimer's disease.

“…Previous frequency estimates for the K polymorphism of 0.12 in UK white subjects were based on enzymatic assays in relatively small groups. "3 14 We therefore genotyped a large sample and obtained a frequency of 0.22 which closely matches that observed in all our other sample groups and in the patient group of Lehmann et al4 This suggests that the original findings may be in fact the result of a type 1 error, to which genetic association studies are known to be prone. "5 Further studies are required to resolve this issue.…”

Reaction to succinylcholine in two patients segregating for the plasma cholinesterase allele Ek

“…The biochemical characteristics of (a) the various cholinesterase variants used by the Danish Cholinesterase Research Unit (1) and (b) some of the new cholinesterase variants used by Evans & Wardell (12) and Whittaker & Britten(16,17).…”