Pseudocholinesterase Variants in Japan

Human butyrylcholinesterase L330I mutation belongs to a fluoride-resistant gene, by expression in human fetal kidney cells

We noticed a Japanese male showed low serum butyrylcholinesterase (BCHE) activity on health examination. The phenotyping analysis revealed a reduced dibucaine number (DN) and an especially low fluoride number (FN), similar to an FS phenotype. A homozygous missense mutation, a T to A transversion at nucleotide 988, was identified in his BCHE gene. This mutation resulted in the replacement of leucine by isoleucine at codon 330 (L330I). DN and FN of recombinant BCHE(L330I) secreted by human fetal kidney cells were compared to recombinant wild-type(usual gene) BCHE and normal serum BCHE. These results showed this amino acid substitution of BCHE, Leu330 to Ile, really caused the abnormal DN and FN. We conclude that the BCHE L330I mutation is a fluoride-resistant gene, a Japanese type fluoride-resistant gene.

Ecogenetic studies in Atacameño Indians

Aldehyde dehydrogenase deficiency, N-acetyltransferase variation and the polymorphisms of alpha 1-antitrypsin, serum cholinesterase, paraoxonase, and delta-aminolevulinic acid dehydratase were investigated in 180 Atacameño Indians from the North of Chile. The genetic predisposition of these individuals for possible atypical reactions against environmental agents and drugs, as well as general implications of these findings, are discussed.

On the geographical distribution of pseudocholinesterase variants

The incidence of pseudocholinesterase (PCHE equals E.C. 3.1.1.8) variants in samples of 8 different population (total of 2218 individuals) is reported. Together with previously mentioned data from the literature, a general survey on the geographical distribution of PCHE isoenzymes is given. Possible reasons for present-day heterogeneity of their distribution are also discussed. Concerning the incidence of the C5 variant, it is pointed out that the validity of applying population genetic models depends upon the accuracy of the genetic basis.

Serum atypical pseudocholinesterase and genetic factors in leprosy

The levels of pseudocholinesterase and its nature were studied in 390 leprosy patients and 343 control subjects. The levels of the enzyme in both leprosy patients and normal controls were comparable. The study of the nature of the enzyme by determining its dibucaine number showed that a statistically significant number of lepromatous patients had the atypical variety of the enzyme compared with normal controls or tuberculoid patients. Since the presence of the atypical variety of the enzyme is genetically determined it is suggested that genetic factors play an important part in deciding susceptibility to lepromatous leprosy.

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.