explained by these polymorphisms for biomarkers of smoking such as carbon monoxide and cotinine will likely be greater.33,34 For example rs16969968 explained four to five times more of the variance in carbon monoxide and cotinine levels compared to self-reported cigarette consumption.32,33 Similarly, we hypothesize that these low frequency and rare CHRNA5 coding variants will explain much more of the variance of these biomarkers.
