Polygenic risk scores are the distillation of the signal, achieved by enormous sample sizes. They work. Fisher showed in 1918 you can perform selection even if

Polygenic risk scores are the distillation of the signal, achieved by enormous sample sizes. They work. Fisher showed in 1918 you can perform selection even if there were an infinite number of loci involved, see https://en.m.wikipedia.org/wiki/Infinitesimal_model https://en.m.wikipedia.org/wiki/Infinitesimal_model