PHARMACOGENETICS Mutational analysis of CYP2C8 in hypertensive patients using denaturing high performance liquid chromatography L. K. Teh* BPharm (Hons) MPharm PhD, M. K. Zahri* MSc, Z. A. Zakaria* MSc PhD, R. Ismail  BPharm (Hons) PharmD and M. Z. Salleh* MSc PhD *Pharmacogenomics Centre (PROMISE), Faculty of Pharmacy, Universiti Teknologi MARA, 40450 Shah Alam, Selangor DE and  Institute for Research in Molecular Medicine, Universiti Sains Malaysia, Health Campus, 16150 Kelantan DI, Malaysia SUMMARY What is known and Objective: CYP2C8 is invol- ved in the cytochrome P450 (CYP) epoxygenase pathway. Arachidonic acid metabolites such as epoxyeicosatrienenoic acids and hydroxyeico- satetrenoic acids, produced may have a role in hypertension. We aimed to develop a medium through-put method for screening samples of known and new mutations of CYP2C8 using denaturing high performance liquid chromato- graphy (DHPLC). Methods: DNA samples from 200 subjects (hypertensive patients and healthy controls) were screened for SNPs in CYP2C8 using DHPLC. Genotypes and allelic frequencies of CYP2C8 between the healthy controls and patients with hypertension were compared. Results and Discussions: Six variants were de- tected and two were new; T deletion at 5063 and substitution of C to T at 33468 in exon 8. Dif- ferences in variant frequencies were detected between the controls and hypertensive patients. The controls have significantly higher preva- lence of C35322C compared to the patients. The functional significance of the SNP at 35322 requires further study. Having homozygous C35322C could be a protective factor for hypertension. What is new and Conclusion: Denaturing high performance liquid chromatography is useful for population screening to identify new and existing SNPs. A higher frequency of the C35322T SNP was observed among hypertensive patients than control subjects. This potentially important observation requires confirmation and the clinical significance assessed. Keywords: CYP2C8, denaturing high performance liquid chromatography (DHPLC), genetic poly- morphism, hypertension, Malaysia, single nucleotide polymorphism (SNP) INTRODUCTION CYP2C8 participates in the metabolism of several therapeutics drugs including paclitaxel, all-trans retinoic acid, varapamil, rosiglitazone, cerivastatin, amiodarone, dapsone and amodiaquine (1–6). It also contributes to activation of toxicologically important compounds including benzo[a]pyrene and parathion (7, 8). CYP2C8 is one of the enzymes involved in the metabolism of arachidonic acid and thus may play a role in the aetiology of cardio- vascular diseases such as hypertension (9). Five variants, CYP2C8*1, CYP2C8*2, CYP2C8*3, CYP2C8*4 and CYP2C8*5, have been detected in African-American and Caucasian (10) and Japanese (11) populations. CYP2C8*2 has an Ile269Phe sub- stitution in exon 5 and CYP2C8*3 includes both Arg139Lys and Lys399Arg amino acid substitu- tions in exons 3 and 8 (10). CYP2C8*4 represents a variant leading to an amino acid change (Ile264Met) change in exon 5 (5). Received 25 June 2009, Accepted 26 October 2009 Correspondence: Mohd. Zaki Salleh, PhD, Professor, Pharmac- ogenomics Centre (PROMISE), Faculty of Pharmacy, Universiti Teknologi MARA, 40450 Shah Alam, Selangor DE, Malaysia. Tel.: +603-55442772; fax: +603-55442725; e-mail: zakisalleh@salam.uitm.edu.my Journal of Clinical Pharmacy and Therapeutics (2010) 35, 723–728 doi:10.1111/j.1365-2710.2009.01146.x Ó 2010 Blackwell Publishing Ltd 723