Recent developments in the field of human genomics have greatly enhanced the potential for precision and
personalized medicine. We have developed a novel
DNA microarray, using a 3-mm square chip coated with
diamond-like
carbon to enhance the signal-to-background ratio, for use as an in vitro diagnostic tool in
precision medicine. To verify the genotyping effectiveness of this newly developed
DNA microarray we examined
UDP-glucuronosyltransferase 1A1 (UGT1A1) polymorphisms in
DNA extracted from patients with metastatic
colorectal cancer. It is established that the polymorphisms of UGT1A1*28 and UGT1A1*6 are significantly associated with severe toxicity induced by the anti-
cancer drug
irinotecan. For each sample, the results obtained with the novel microarray platform were compared with those obtained using other, more established, methods, including direct sequencing and the Invader assay. The polymorphisms tested included a single
nucleotide substitution (UGT1A1*6) and a TA-repeat polymorphism (UGT1A1*28), both of which were detected simultaneously and accurately using our method. Moreover, our method required 1.5-fold less time to assay and 20-fold less sample than those required by the Invader assay. In summary, our newly developed
DNA microarray is more practical than established methods, and is at least as accurate; this will increase the efficiency of polymorphism detection prior to diagnosis and the commencement of treatment, and can feasibly be applied in
precision medicine.