Assessment of CYP2C19 genetic polymorphisms in a Korean population using a simultaneous multiplex pyrosequencing method to simultaneously detect the CYP2C19*2, CYP2C19*3, and CYP2C19*17 alleles.

BACKGROUND AND OBJECTIVE: CYP2C19 is a drug-metabolizing enzyme showing various genetic polymorphisms that may cause marked interindividual and interethnic variability in the disposition of its substrates. We assessed CYP2C19 genetic polymorphisms in a Korean population using a newly developed multiplex pyrosequencing method. METHOD: A multiplex pyrosequencing method to simultaneously detect CYP2C19*2, *3, and *17 alleles was designed. We established the frequency of these CYP2C19 alleles in 271 Korean subjects using the multiplex pyrosequencing method. RESULTS: The results showed 100% concordance between single and multiplex pyrosequencing methods. We also validated the polymorphisms identified by pyrosequencing with direct sequencing method. The allele frequencies of CYP2C19*2, CYP2C19*3, and CYP2C19*17 were 0·284, 0·101 and 0·015 respectively. These frequencies are similar to that reported for other Asian populations including Japanese and Chinese but different from that of Caucasians and Africans. CONCLUSIONS: The multiplex pyrosequencing method to detect CYP2C19*2, CYP2C19*3, and CYP2C19*17 concurrently, seems to be a rapid and reliable genotyping method for the detection of important CYP2C19 genetic polymorphisms. Similar to studies conducted on other Asian populations, this study reported that in the Korean population tested, the CYP2C19*2 and CYP2C19*3 alleles were relatively frequently found, whereas the frequency of CYP2C19*17 was very low.

Direct assessment of international consistency of standards for ground-level ozone: strategy and implementation toward metrological traceability network in Asia.

An international exercise to directly assess consistency of standards for ground-level ozone in East Asia was conducted as part of the East Asian Regional Experiment 2005 (EAREX 2005) in the framework of the Atmospheric Brown Clouds (ABC) project. Ten organizations collaboratively participated in the intercomparison. Four groups representing Japan, Korea, Hong Kong, and Taiwan made comparisons at the Gosan super observatory, Jeju Island, Korea, in March 2005, with ozone instruments calibrated to their national standards, and four Japanese groups made off-site comparisons with laboratory-level standards. All comparisons generally indicated good agreement with the standard reference photometer (SRP) 35, built by the National Institute of Standards and Technology (USA) and maintained by the National Institute for Environmental Studies (Japan). The assessment was expanded to measurement networks contributing to the World Meteorological Organization's Global Atmospheric Watch (WMO/GAW) program as part of off-site comparisons, and excellent agreement was achieved. These efforts contribute to propagating traceability of the national metrology standards among the atmospheric science community, to ensuring comparability of the existing ozone measurements, and to establishing an integrated network of air quality monitoring in Asia.