I am using unconditional logistic regression to modelise genetic effect and genetic*environment exposure effect on my outcome.
My results a bit strange :
When modeling only main variants effect, I have no SNP associated
When modeling with interaction term exposure:SNP with additive term , I have a strong significant signal only for additive term ( towo SNP with p<<10e-8) and nothing for interaction.
I am using 0,1 and 2 codes for SNP (effect allele) and a continuous exposure variable.
I am working on case control study ( 2300 subjects) and testing 7000 SNPs
Can this be a reliable result ? How could this be explained ?
Thank you very much !