Smoking behavior is influenced by several conditions, including environmental, genetic and epigenetic. One such epigenetic mechanism that contributes to smoking behavior is DNA methylation (DNAM).
However, the pattern of inheritance of DNA methylation is unknown. The erasure of DNAM of all genes (except imprinted ones) contradicts with the belief that it is vertically transmitted. We propose that inheritance of DNA methylation of from grandmother (F0) to grandchildren (F2) is conditional upon in utero exposure in the mother(F1). We use a CpG site cg05575921 of the AHRR gene to demonstrate the inheritance of DNAM.
Additionally, we also propose that maternal smoking mediated differential DNAM of cg05575921 also affects the time of initiation of smoking in the offspring. The primary analysis was done using the study population from the Isle of Wight cohort (UK). We intend to replicate our finding using the data from ALSPAC.