Background: While spouse correlations have been documented for numerous traits, no prior studies have assessed assortative mating for genetic ancestry in admixed populations.Results: Using 104 ancestry informative markers, we examined spouse correlations in genetic ancestry for Mexican spouse pairs recruited from Mexico City and the San Francisco Bay Area, and Puerto Rican spouse pairs recruited from Puerto Rico and New York City. In the Mexican pairs, we found strong spouse correlations for European and Native American ancestry, but no correlation in African ancestry. In the Puerto Rican pairs, we found significant spouse correlations for African ancestry and European ancestry but not Native American ancestry. Correlations were not attributable to variation in socioeconomic status or geographic heterogeneity. Past evidence of spouse correlation was also seen in the strong evidence of linkage disequilibrium between unlinked markers, which was accounted for in regression analysis by ancestral allele frequency difference at the pair of markers (European versus Native American for Mexicans, European versus African for Puerto Ricans). We also observed an excess of homozygosity at individual markers within the spouses, but this provided weaker evidence, as expected, of spouse correlation. Ancestry variance is predicted to decline in each generation, but less so under assortative mating. We used the current observed variances of ancestry to infer even stronger patterns of spouse ancestry correlation in previous generations.Conclusions: Assortative mating related to genetic ancestry persists in Latino populations to the current day, and has impacted on the genomic structure in these populations.
Bibliographical noteFunding Information:
The authors would like to acknowledge the families and the patients for their participation and the numerous health care providers and community clinics for their support and participation in the GALA Study. We would like to especially thank Jeffrey M Drazen, MD, Scott Weiss, MD, Ed Silver-man, MD, PhD, Homer A Boushey, MD, Jean G Ford, MD and Dean Shep-pard, MD for all of their effort towards the creation of the GALA Study. We are also indebted to Dr Mark Shriver for providing ancestral allele frequency data. This work was supported by National Institutes of Health (HL078885, HL088133, U19 AI077439, ES015794), Flight Attendant Medical Research Institute (FAMRI), and the RWJ Amos Medical Faculty Development Award to EGB, American Thoracic Society 'Breakthrough Opportunities in Lung Disease' (BOLD) Award and Tobacco-Related Disease Research Program New Investigator Award (15KT-0008) to SC, Beat-riu de Pinos Postdoctoral Grant (2006 BP-A 10144) to MV, the Ernest S Bazley Grant to PCA, and the Sandler Center for Basic Research in Asthma and the Sandler Family Supporting Foundation.