The goal of the current study was to perform a meta-analysis specifically targeting early smoking phenotypes and SNPs in the CHRNA5/CHRNA3/CHRNB4 gene cluster. These analyses were undertaken to determine: (1) whether the most robust association signal in this region shown for other smoking behaviors (rs16969968) is also seen for age of smoking initiation and age of onset of regular smoking, and/or: (2) if additional statistically independent signals are important in adolescent initiation of tobacco use and progression to regular smoking.
