Cross‑population LD recovers family‑GWAS signals

When strict family‑based genome‑wide association results leave almost no individually significant variants, coordinated allele‑frequency patterns across populations (cross‑population linkage disequilibrium) can be used as a targeted filter to pull out weak, diffuse directional signals that standard clumping throws away. This is not about improving within‑population prediction but about detecting systematic shifts consistent with polygenic adaptation across groups. — If valid, the method alters whether and how researchers (and non‑specialist audiences) can claim genetic differences between populations — changing scientific and political conversations about genetics and group traits.