Re.: 'Genetic association and gene-environment interaction: a new method for overcoming the lack of exposure information in controls'.

摘要

We read with interest the recent paper by Kazma et al. (1), in which the authors propose a multinomial analysis to jointly test for genetic (G) and gene-environment interaction (Gx E) effects using a reference control group for whom one has genotypes but no other data. The proposed logistic regression test makes clever use of a method developed for phenotypic subcategories, by treating exposed and unex-posed cases as if they had separate phenotypes. The authors show that the resulting joint hypothesis test is powerful, sometimes even more powerful than a full case-control analysis. We wish to offer some clarifications and cautions related to that proposed analysis.