Singapore Pharmacogenomics Portal: a web resource for evaluating human genetic variations of genes responsible for drug responses

Tailoring of recommendations to reduce serious cutaneous adverse drug reactions: a pharmacogenomics approach

The Health Sciences Authority launched a pharmacogenetics initiative in 2008 to facilitate evaluation of pharmacogenetics associations pertinent for Chinese, Malays and Indians in Singapore. The aim was to reduce the incidence and unpredictability of serious adverse drug reactions, with a focus on serious skin adverse drug reactions. This paper describes the gathering of evidence and weighing of factors that led to different genotyping recommendations for HLA-B*15:02 with carbamazepine and HLA-B*58:01 with allopurinol, despite both having strong genetic associations. Translation of pharmacogenomics at a national level requires careful deliberation of the prevalence of at-risk allele, strength of genetic associations, positive predictive value, cost-effectiveness and availability of alternative therapies. Our experience provides a perspective on translating genomic discoveries in advancing drug safety.

A cluster of Epoetin-associated pure red cell aplasia: clinical features and the possible association of HLA-DRB1*12:02

Antibody-mediated pure red cell aplasia is a rare but serious complication in chronic kidney disease patients receiving recombinant human erythropoietin (r-HuEpo). Between April 2012 and May 2013, eight such cases were reported in our institution. Their clinical features were reviewed and their HLA alleles were compared with those of healthy controls. All patients were exposed to epoetin alfa (Eprex^®) with polysorbate-80 as stabilizer via subcutaneous route with a mean age of 61.9 years and mean exposure of 11.2 months of r-HuEpo before loss of efficacy. 87.5% of the cases were male and Chinese and received immunosuppression as treatment for pure red cell aplasia. All three of the successfully treated patients are alive compared with only 40% of the transfusion-dependent patients. DRB1*12:02 was more frequently expressed among the cases than healthy controls suggesting a plausible molecular link.