The genetic association studies need to be adjusted for the covariates such as Age, Gender etc. Is there a statistical way to figure out that? And is it required that all these covariates should be transformed to the same scale before using in the multivariable regression?
You might find this attachment of some interest. Best wishes, David Booth
Alagu Sankareswaran , as you mentioned multivariate regression is a way of doing what you want, and no, there is no need in principle to estimate the regression with the variables in the same scale (but this depends also in what you want to achieve with your model).
Hello Alagu Sankareswaran :
Yes, for genetic association analysis the phenotypes need to be adjusted.
In summary, the first step is to think about all non-genetic factors that may influence your phenotypes (a good search in the literature will certainly be helpful here). After that, you need to test if these effects are significant in your data, using adequate statistical tests.
I have some materials that might be helpful to you. Send me your email if interested.