Pharmacogenetic testing in the UK clinical setting

Mark J Bartlett a, David W Green b, Elizabeth A Shephard a

Pharmacogenetic studies grow in number and power, but translation of knowledge into the clinical setting has been slow. The USA leads the world in the use of genetic information to support decision making for drug prescription, but the use is far from routine. Recently the RAPID GENE study1 showed early proof-of-concept for the benefit of point-of-care genotyping of CYP2C19 to personalise antiplatelet therapy in patients undergoing percutaneous coronary intervention. This study built on a meta-analysis, showed poor efficacy of clopidogrel when a patient had CYP2C19*2 and CYP2C19*3 allele variants.2 The American Food and Drug Administration responded by releasing boxed warnings for clopidogrel. The UK has been slower in the adoption of genetic testing for drug therapy, with few laboratories offering the service and a limited number of tests being requested.

To assess whether physicians' opinion is acting as a barrier to the adoption of genetic testing in drug prescription processes in the UK we designed a quantitative online survey. 87% of the 701 respondents were from Speciality Registrar or Consultant level. Opinions were sought on the usefulness of pharmacogenetics in the clinical setting, and were assessed on a Likert scale (1=strongly disagree and 5=strongly agree). The average opinion score was 3·6, suggesting that clinicians' views on pharmacogenetics are positive.

Respondents also rated their confidence in pharmacogenetic information (0—3 scale; 0 being not confident, and 3 very confident). Only 15 respondents scored 3, 81 scored 2, 252 scored 1, and 241 scored 0. 89% of respondents had received no formal training in pharmacogenetics. Confidence in the use of pharmacogenetic information increases significantly with the time of courses received on the topic (figure). Factors such as sex, age, ethnic origin, place of training, or place of employment are not significantly correlated with opinions, confidence, or information.

Figure Full-size image (24K) Download to PowerPoint

Confidence in pharmacogenetics and information received

0=not confident to 3=very confident. Responses are presented according to time (h) of pharmacogenetics courses received. The average confidence in pharmacogenetic information varies with the time of courses received (p <0 div="" kruskal-wallis="" test="">

More training in pharmacogenetics is needed to increase the adoption in the UK of genetic testing for drug efficacy or adverse effects. This aim can be achieved by enhanced teaching of pharmacogenetics in medical school curricula and through continued professional development courses.

MJB is cofounder of Geneix Ltd. The other authors declare that they have no conflicts of interest.

References

1 Roberts JD, Wells GA, Le May MR, et al. Point-of-care genetic testing for personalisation of antiplatelet treatment (RAPID GENE): a prospective, randomised, proof-of-concept trial. Lancet 2012; 379: 1705-1711. Summary | Full Text | PDF(198KB) | CrossRef | PubMed

2 Mega JL, Simon T, Collet JP, et al. Reduced-function CYP2C19 genotype and risk of adverse clinical outcomes among patients treated with clopidogrel predominantly for PCI: a meta-analysis. JAMA 2012; 304: 1821-1830. CrossRef | PubMed

a Institute of Structural and Molecular Biology, University College London, London WC1E 6BT, UK

b Division of Psychology and Language Sciences, University College London, London, UK