Should I standardize age and age2 as covariates in GWAS models?

Question

[yu]

I have a question regarding covariate adjustment in GWAS. In my GWAS model, I am adjusting for both linear and quadratic age effects:

Phenotype ~ Genotype + Age + Age2 + other covariates.

I wonder whether I should standardize age before including it in the model to avoid the multicollinearity of age and age2.

Is there any common practice in large GWAS consortia regarding this?

Any advice or references would be greatly appreciated!