Genetic Polymorphisms of the Carboxylesterase 1 (CES1) Gene in a Korean Population

ABSTRACT

Human carboxylesterase 1 (CES1) is a serine esterase that hydrolyzes various exogenous compounds. Single nucleotide polymorphisms (SNPs) of CES1 may lead to inter-individual metabolic variability of its substrates. The allele and haplotype frequencies of known SNPs have been demonstrated to vary among ethnic groups. We analyzed genetic variations of CES1 in a Korean population. Direct sequencing of all exons and flanking regions of the CES1 gene was performed on samples obtained from 200 Koreans. We identified 41 SNPs. The most frequent SNPs was -914G>C (frequency 99.5%), followed by 4256G>A (frequency 65.8%), -75T>G (frequency 59.3%). Haplotype analysis using the identified SNPs revealed fifteen haplotypes (> or =1% haplotype frequency) in our samples. The most frequent haplotype was Hap1 (frequency 15.4%). Among the identified 41 SNPs, nine of which are novel variants and 14 SNPs were nonsynonymous variants. Using the functional predictive software PolyPhen-2, the G19V, E221G, and A270S variants were predicted to be most likely damaging to the function and structure of CES1. In-vitro analyses for two of these variants have been previously performed; however, functional evaluation of E221G (11657A>G, rs200707504) still needs to be conducted. Therefore, further studies are warranted to characterize the functional impact of E221G on CES1 activity.