Discover and read the best of Twitter Threads about #genepitwitter
Most recents (2)
Okay #epitwitter and #genepitwitter, let’s talk about how statistical and biological gene-environment interactions relate to each other (or not). \thread (part 1)
TL;DR 1: the distribution of a trait conditional on genotype and exposure at the population level (whether there is a statistical interaction or not) is consistent with 1,000s of possible biological models.
TL;DR 2: conversely, knowing that a gene product and an exposure or exposure byproduct physically interact at the molecular or cellular level need not say anything about what’s happening at the population level.
I found the discussion of Quetelet and populations at the beginning of Chapter 3 of Epidemiology and the People’s Health particularly instructive, especially for genetic epidemiology. #epibookclub #epipeopleshealth #gwas #genepitwitter 1/18 
The question “who—or what—determines populations or groups that merit comparison” is an important but tetchy one. 2/18
The concept of “population stratification bias” in genetic epidemiology is usually introduced using a toy example: say we’re studying two populations, with random mating within but no mating across populations. 3/18
