Genetic footprints of assortative mating in the Japanese population

Assortative mating (AM) is a pattern characterized by phenotypic similarities between mating partners. Detecting the evidence of AM has been challenging due to the lack of large-scale datasets that include phenotypic data on both partners, especially in populations of non-European ancestries. Gametic phase disequilibrium between trait-associated alleles is a signature of parental AM on a polygenic trait, which can be detected even without partner data. Here, using polygenic scores for 81 traits in the Japanese population using BioBank Japan Project genome-wide association studies data (n = 172,270), we found evidence of AM on the liability to type 2 diabetes and coronary artery disease, as well as on dietary habits. In cross-population comparison using United Kingdom Biobank data (n = 337,139) we found shared but heterogeneous impacts of AM between populations. Yamamoto et al. find genetic evidence of assortative mating based on dietary habits and disease phenotypes in the Japanese population, and show that this pattern of partner choice is markedly different from its European-ancestry counterpart.

Automated summary

This study provides genetic evidence of assortative mating based on dietary habits and disease phenotypes in the Japanese population, and demonstrates that this pattern of partner choice is markedly different from its European-ancestry counterpart.