The unadjusted PRS is the sum of all genetic markers across the genome, weighted by their marginal effect size estimates. More specifically, the unadjusted polygenic score for the i-th individual is \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathrm{PRS}}_i = \mathop {\sum}\nolimits_{j = 1}^M X_{ij}\hat b_j$$\end{document}PRSi= ∑j=1MXijb^j, where M is the total number of genetic markers, Xij is the genotype for the i-th individual and the j-th SNP, and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hat b_j$$\end{document}b^j is the estimated marginal per-allele effect size of the j-th SNP.
