title: Genetic polymorphisms of CYP2C9 and CYP2C19 are not related to drug-induced idiosyncratic liver injury (DILI).
abstract: OBJECTIVE
  The general view on the pathogenesis of drug-induced idiosyncratic liver injury (DILI) is that parent compounds are rendered hepatotoxic by metabolism, mainly by cytochrome (CYP) 450, although other metabolic pathways can contribute. Anecdotal reports suggest a role of CYP 450 polymorphisms in DILI. We aimed to assess in a series of Spanish DILI patients the prevalence of important allelic variants of CYP2C9 and CYP2C19, known to be involved in the metabolism of several hepatotoxic drugs.
  
  
  METHODS
  Genotyping of CYP2C9 ((*)2, (*)3) and CYP2C19 ((*)2 and (*)3), was carried out in a total of 28 and 32 patients with a well established diagnosis of DILI. CYP2C9 and CYP2C19 variants were analysed in genomic DNA by means of PCR-FRET and compared with previous findings in other Caucasian populations.
  
  
  RESULTS
  CYP2C9 and CYP2C19 allele and genotype frequencies were in agreement with Hardy-Weinberg equilibrium. Fourteen patients (50%) were heterozygous and 1(4%) found to be compound heterozygous for the CYP2C9 allele. Seven (22%) were found to carry one and 1(3%) carried two CYP2C19 mutated alleles. No patients were homozygous for (*)3 allele. The distribution of both CYP2C9 and CYP2C19 allelic variants in DILI patients were similar to those in other Caucasian populations. Patients with variant and those with wild-type alleles did not differ in regard to clinical presentation of DILI, type of injury and outcome.
  
  
  CONCLUSIONS
  We find no evidence to support CYP2C9 and CYP2C19 genetic polymorphisms as predictable potential risk factors for DILI.
authors.affiliation: Servicio de Farmacología Clínica, Grupo de Estudio para las Hepatopatías Asociadas a Medicamentos, Co-ordinating Centre, Hospital Universitario Virgen de la Victoria, Facultad de Medicina, Campus Universitario de Teatinos s/n, Málaga, Spain.
authors.forename: K
authors.initials: K
authors.lastname: Pachkoria
authors.forename: M I
authors.initials: MI
authors.lastname: Lucena
authors.forename: F
authors.initials: F
authors.lastname: Ruiz-Cabello
authors.forename: E
authors.initials: E
authors.lastname: Crespo
authors.forename: M R
authors.initials: MR
authors.lastname: Cabello
authors.forename: R J
authors.initials: RJ
authors.lastname: Andrade
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D001189:Aryl Hydrocarbon Hydroxylases / Q000235:genetics*; D056486:Chemical and Drug Induced Liver Injury / Q000201:enzymology* / Q000235:genetics*; D065731:Cytochrome P-450 CYP2C19; D065729:Cytochrome P-450 CYP2C9; D005260:Female; D005787:Gene Frequency; D014644:Genetic Variation; D006801:Humans; D008099:Liver / Q000187:drug effects* / Q000201:enzymology / Q000293:injuries*; D008297:Male; D008875:Middle Aged; D006899:Mixed Function Oxygenases / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D012307:Risk Factors; D013030:Spain
chemical_list: D006899:Mixed Function Oxygenases; C450260:CYP2C9 protein, human; D065729:Cytochrome P-450 CYP2C9; D001189:Aryl Hydrocarbon Hydroxylases; C045793:CYP2C19 protein, human; D065731:Cytochrome P-450 CYP2C19