Muh gene-environemnt interactions. Even worse than normal candidate genes approach. https://www.repository.cam.ac.uk/handle/1810/264528 … #genomicspic.twitter.com/DPP8sdOB5K
People are mostly interested in the main effect, which is what twin studies etc. capture. You can try to find these interaction effects, but I wouldn't be very hopeful if I were you. Child x parent interaction is mostly evocative genetic-environment correlation.