title: Allele and genotype frequency of CYP2C19 in a Tamilian population.
abstract: OBJECTIVE
  To investigate the frequencies of CYP2C19*1, CYP2C19*2 and CYP2C19*3 alleles and CYP2C19 genotypes in a Tamilian population.
  
  
  METHODS
  The study was conducted in 112 unrelated healthy human volunteers. DNA was extracted from leucocytes and analyzed by the PCR-RFLP protocol. The PCR product was digested with restriction enzymes (SmaI and BamH1) and then separated electrophoretically using polyacrylamide gel.
  
  
  RESULTS
  The frequencies of the CYP2C19*1, *2 and *3 alleles were 0.598 [95% confidence interval (CI) 0.507, 0.689], 0.379 (95% CI, 0.350,0.407) and 0.022 (95% CI -0.005, 0.049), respectively. The distribution of CYP2C19*1/*1,*1/*2, *1/*3, *2/*2 and *2/*3 genotypes were 0.295 (95% CI, 0.210, 0.379), 0.580 (95% CI, 0.488, 0.671), 0.027 (95% CI -0.003, 0.057), 0.080 (95% CI 0.030, 0.130) and 0.018 (95% CI -0.006, 0.042), respectively.
  
  
  CONCLUSIONS
  The distribution of CYP2C19*1/*1 in the Tamilian population is lower than that in Caucasians, Africans and the North Indian population. The CYP2C19*1/*2 is significantly higher in Tamilians when compared with other populations. The CYP2C19*1/*3 allele, which was not reported in the North Indian and Caucasian populations has been identified in 2.7% of the Tamilian population.
authors.affiliation: Pharmacogenomics Laboratory, Department of Pharmacology, Jawaharlal Institute of Postgraduate Medical Education and Research, Pondicherry-605006, India. adithan@vsnl.com
authors.forename: C
authors.initials: C
authors.lastname: Adithan
authors.forename: N
authors.initials: N
authors.lastname: Gerard
authors.forename: S
authors.initials: S
authors.lastname: Vasu
authors.forename: J
authors.initials: J
authors.lastname: Rosemary
authors.forename: C H
authors.initials: CH
authors.lastname: Shashindran
authors.forename: R
authors.initials: R
authors.lastname: Krishnamoorthy
mesh_terms: D000328:Adult; D001189:Aryl Hydrocarbon Hydroxylases / Q000235:genetics*; D065731:Cytochrome P-450 CYP2C19; D005260:Female; D005787:Gene Frequency; D005828:Genetics, Population; D005838:Genotype; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D007194:India / Q000208:ethnology; D008297:Male; D006899:Mixed Function Oxygenases / Q000235:genetics*; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length
chemical_list: D006899:Mixed Function Oxygenases; D001189:Aryl Hydrocarbon Hydroxylases; C045793:CYP2C19 protein, human; D065731:Cytochrome P-450 CYP2C19