Patterns of admixture in Latino populations

RUIZ-LINARES A, WANG S, BEDOYA G, BORTOLINI C, NICOLINI H, KLITZ W, MOLINA J, FREIMER N, BARRANTES R, MAZZOTTI G, GALLO C, DIPIERRI J, ALFARO E, BIANCHI NO, BAILLIET G, ROTHHAMMER F, SALZANO F, FELDMAN M, ROSENBERG M

New Orleans, USA

Congreso; American Society Human Genetics 56th Annual Meetings; 2006

American Society of Human Genetics

We examined the diversity of 13 Latino populations from seven countries (Mexico, Guatemala, Costa Rica, Colombia, Chile, Argentina and Brazil) typing 745 autosomal microsatellite markers in 250 individuals. Estimates of genetic ancestry for these populations varied substantially. Native American ancestry varied between 19.6% and 70.3%, European ancestry between 26.9% and 70.6%, and African ancestry between 1.1% and 9.8%. Genetic structure analysis provides evidence of a genetic continuity between pre- and post-Columbian populations for specific geographic regions. For instance, a Chibchan-Paezan ancestry is detectable in Latinos from lower Central America and northwest South America. Individual admixture estimates vary considerably between populations. Some Latinos (e.g. Mexico City) show marked variation in individual admixture, whereas others (e.g. Antioquia and Costa Rica) show little variation. This variation is likely to reflect the history of admixture of each geographic region examined: some Latino populations are still undergoing substantial admixture whereas others underwent admixture mostly in early colonial times. These results have important implications for admixture mapping and association mapping studies in Latino populations