DNA methylation in peripheral tissues and left-handedness.
Odintsova VV., Suderman M., Hagenbeek FA., Caramaschi D., Hottenga J-J., Pool R., BIOS Consortium None., Dolan CV., Ligthart L., van Beijsterveldt CEM., Willemsen G., de Geus EJC., Beck JJ., Ehli EA., Cuellar-Partida G., Evans DM., Medland SE., Relton CL., Boomsma DI., van Dongen J.
Handedness has low heritability and epigenetic mechanisms have been proposed as an etiological mechanism. To examine this hypothesis, we performed an epigenome-wide association study of left-handedness. In a meta-analysis of 3914 adults of whole-blood DNA methylation, we observed that CpG sites located in proximity of handedness-associated genetic variants were more strongly associated with left-handedness than other CpG sites (P = 0.04), but did not identify any differentially methylated positions. In longitudinal analyses of DNA methylation in peripheral blood and buccal cells from children (N = 1737), we observed moderately stable associations across age (correlation range [0.355-0.578]), but inconsistent across tissues (correlation range [- 0.384 to 0.318]). We conclude that DNA methylation in peripheral tissues captures little of the variance in handedness. Future investigations should consider other more targeted sources of tissue, such as the brain.