Hi all, I am dealing with couple of SNPs to predict the risk. As suggested by several references, wGRS or PRS will be the good choice. However, most refs used quantile 1 as average risk (20% proportion), quantiles 2-4 as intermediate risk, and quantile 5 as high risk. I am confusing that if the incidence of the disease is less than 1%, how can we say 20% individuals will be at high risk? Is there any other better soltion?
An other question is that some alleles were reported as risk alleles with <1 OR, which means the allele is "protective", should we inverse the OR and change the other allele as risk to calculate the GRS? If not, I think the category of outcomes should contain low risk, which means the outcomes should be grouped into low risk, below average risk, average risk, above average risk, and high risk?
Could any one give me some suggestions?