Genetical studies on a new variant of serum cholinesterase detected by electrophoresis

Abstract

Summary 1. At least four distinct zones with properties of serum cholinesterase (pseudocholinesterase) may be demonstrated by starch gel electrophoresis of normal serum or plasma. These have been called C1; C2, C3 and C4, and they have been observed in all the sera or plasmas studied. Most of the serum cholinesterase activity present is attributable to C4. C1( C2 and C3 are only minor components. In paper electrophoresis at pH 8·6, C1, C2, C3 and C4 have essentially the same mobility. Since they are well separated at this pH in starch gel electrophoresis it seems likely that they may represent a series of polymers of increasing molecular weight C1 < C3 < C4. C2 has a slightly greater mobility than C1, C3 and C4 in paper electrophoresis at pH 8·6. 2. In some individuals a further zone (C5) with properties of serum cholinesterase is present in addition to zones C1; C2, C3 and C4. C5 has a slightly lower mobility than C4 both in paper and starch gel electrophoresis at pH 8·6. The separation of C5 from C4 is improved in starch gel electrophoresis at pH 6·0. 3. Of 248 unrelated British individuals studied, 13 5% were found to be C5+. Of 213 Tristan da Cunha islanders studied 36 17% were found to be C5+. The incidence of the C5+ phenotype did not vary significantly in different age groups, or between the two sexes. 4. In the British population 96 % had the ‘usual’ serum cholinesterase phenotype as denned by dibucaine and fluoride number determination, and 4% had the ‘intermediate’ phenotype. All the C5+ individuals had the ‘usual’ phenotype. In the Tristan da Cunha islanders all individuals studied had the ‘usual’ phenotype. The mean DN and FNs for the C5+ individuals did not differ significantly from the mean DN and FNs of C5− individuals with the ‘usual’ phenotype. 5. The mean level of serum cholinesterase in C5+ individuals was about 30% higher than that of C5− individuals of the ‘usual’ phenotype. The difference was highly significant. This result suggests that the C5 component may be an extra component with no direct homologue in C6−individuals. 6. Studies on sixty relatives of nine randomly selected C5+ individuals from the British population showed a highly significant familial concentration of C5+. The pedigrees suggest that C5+ individuals may be heterozygous for a gene determining the formation of the C5 component. The distribution of the Cs+ phenotype in the complex pedigree of the Tristan da Cunha islanders was also found to be consistent with this hypothesis. If the hypothesis is correct then one must assume that not all presumptive heterozygotes exhibit the C5 component, because occasional instances of C5+ individuals both of whose parents were C5− were observed. There is, however, considerable variation among C5+ individuals in the amount of the C6 component present, and it is quite possible that the methods used here might have failed to detect the component if it were present only in very small amounts. We are grateful to the Medical Research Council Working Party on Tristan da Cunha for providing the ...

Increased plasma cholinesterase activity and succinylcholine resistance: a genetic variant.

“…This band was reported to be present in 10% of a random sample of the British population (15). However, the cholinesterase activity found in individuals with this phenotype, although slightly higher than usual, was much lower than for the subjects of the present report.…”

“…The two pale bands closest to the origin represent storage bands. Harris and associates believe that they may be derived from the more intense C4 band after a few days' storage (15 The staining characteristics of the additional band suggested that it contributed more to the total cholinesterase activity than the other bands. In three of the four affected family members, the extra band stained more intensely and diffusely than the C4 band and was much darker than C1, C2, or C3.…”

“…Harris, Hopkinson, Robson, and Whittaker detected a further phenotype that can only be demonstrated electrophoretically (15). Family studies suggested that the extra band they reported is due to a gene that is nonallelic to the previously described genes (16).…”

Butyrylcholinesterase and obesity in individuals with the CHE2 C5+ and CHE2 C5− phenotypes

“…With the exclusion of one BCHE UA individual from the 16 CHE2 C5 þ obese individuals (Table 2), mean total BChE activities were 5.8370.97 and It is a well-known fact that the CHE2 C5 þ phenotype presents higher mean BChE total activity than the CHE2 C5À phenotype as shown in samples from different general populations. 5,9,11,[20][21][22] Although this difference between the mean BChE activities of these two phenotypes occurs in the general population, the data in Table 2 show that there was no difference in total mean BChE activity between CHE2 C5 þ and CHE2 C5À obese individuals (t ¼ 0.07; P40.90). In a previous study on CHE2 C5 þ individuals from a population sample, positive correlations between weight and total and AC OF BChE activities were shown.…”

Pseudocholinesterase Polymorphism among &Ccedil;ºlanders (Finno-Swedes), Maris (Cheremisses, USSR) and Greenland Eskimos, and the Segregation of some E₁ and E₂Locus Types in Finnish Lapp Families

“…About 10% normal Europeans show the presence of another band slightly less mobile than the major C4 band. The presence of this C5 band seems to be genetically controlled by another locus E._, [Harris era/., 1963;Ashton andSimpson, 1966: Altland era/., 1969], The C5+ allele seems to show dominance over its silent counterpart C5+ [Harris et a/., 1963], The indi viduals with C5+ phenotypes show about 25-30% more PCHE activity than that of the normal individuals [Harris et at., 1963: Altland el al., 1969, G allango and Arends [1969] found a significant, high incidence (22%) of the C-+ variant in myeloma patients as compared to 8.5% in normal Venezuelian population.…”