A validated restriction enzyme ddPCR cg05575921 (AHRR) assay to accurately assess smoking exposure.

ABSTRACT

BACKGROUND & METHODS: In this study, a novel restriction enzyme (RE) digestion-based droplet digital polymerase chain reaction (ddPCR) assay was designed for cg005575921 within the AHRR gene body and compared with matching results obtained by bisulfite conversion (BIS) ddPCR and Illumina DNA methylation array. RESULTS: The RE ddPCR cg05575921 assay appeared concordant with BIS ddPCR (r2 = 0.94, P < 0.0001) and, when compared with the Illumina array, had significantly better smoking status classification performance for current versus never smoked (AUC 0.96 versus 0.93, P < 0.04) and current versus ex-smoker (AUC 0.88 versus 0.83, P < 0.04) comparisons. CONCLUSIONS: The RE ddPCR cg05575921 assay accurately predicts smoking status and could be a useful component of 'precision-medicine' chronic disease risk screening tools.