We will analyse the association between various smoking phenotypes in YPs and mothers and common genetic variation (GWAS, available for most YPs and mothers) and more rare genetic variation (based on GWAS data imputed to a novel imputation panel based on sequencing data, therefore available for most YPs and mothers, as well as on a subsample of the cohort with UK10K sequencing data).

YPs Analyses

Phenotypes to be analysed will include initiation, age at initiation, first response to tobacco, tobacco intake (as indexed by daily cigarette consumption), and level of nicotine dependence (based on the FTND questionnaire). Both cross-sectional measures and derived life-time consumption measures will be used. Where possible and appropriate, trajectories of use will be defined as part of an ongoing collaboration with Prof Matt Hickman and Dr Jon Heron.

Mothers Analyses

Phenotypes to be analysed will include initiation, age of initiation, tobacco intake (as indexed by daily cigarette consumption), level of nicotine dependence, and smoking cessation. Both cross-sectional measures and derived life-time consumption measures will be used.

A detailed analysis plan for the GWAS of individual studies to be included in the GSCAN collaboration is available online (http://gscan.sph.umich.edu/gwas/analysis_plan).