detect. Genetic risk scores (GRSs) summarize risk-associated variation across the genome 9 by aggregating information from multiple risk SNPs (the simplest GRSs count disease-associated alleles). Because GRSs pool information from multiple SNPs, each individual SNP is less important to the summary measurement and the “signal” from the GRS is robust to imperfect linkage for any one SNP. For the same reason, GRSs are less sensitive to minor allele frequencies for individual SNPs. As the number of SNPs included in a GRS grows, the distribution of values approaches normality, even when individual risk alleles are relatively uncommon 10. Therefore, the GRS can be an efficient and effective means of constructing genome-wide risk measurements from GWAS findings.
