Abstract

BARQUERA, Rodrigo  and  GRANADOS, Julio. La diversidad biológica en los haplotipos del sistema HLA en las poblaciones mestizas de México. Cuicuilco [online]. 2013, vol.20, n.58, pp.197-225. ISSN 0185-1659.

Population genetic studies describing the Major Histocompatibility Complex (MHC) polymorphism have shown that specific human leucocyte (HLA) alleles and haplotypes may distinguish the genetic admixture of individuals and populations as well. The aim of this work is to present in Mexicans (Amerindian and Mestizos) the genetic diversity of MHC blocks and discuss, from an evolutionary-adaptive and historical-demographical point of view, the presence of Native American, African, Asian and European variants and its associations in various human groups. This work analyses data on HLA-A, -B, -DRB1, and -DQB1 haplotypes and includes information of class I and class II variation, linkage disequilibrium analysis, Hardy-Weimberg equilibrium, and admixture estimates in individuals from Aguascalientes, Mexico City (which includes Distrito Federal, Mexico State and Hidalgo), Coahuila, Durango, Guanajuato, Jalisco, Michoacán, Morelos, Nuevo León, Oaxaca, Puebla, Querétaro, Sinaloa, Sonora, Tabasco, Tamaulipas, Tlaxcala, Veracruz, Yucatán, and Zacatecas. Results show that the HLA-B locus is the most polymorphic one, particularly when HLA-B/-DRB1 combinations are included. We also were able to identify representative haplotypes from ancestral populations that contributed to the genetic pools in distinct populations of Mexico; the most representative are HLA-A*02/-B*39/-DRB1*04/-DQB1*03:02 (Native American), -A*29/-B*44/-DRB1*07/-DQB1*02 (European), -A* 30/-B*42/-DRB1*03:02/-DQB1*04 (African), -A*30/-B*18/-DRB1*15/-DQB1*06 (Asian). In summary Modern Mexicans genetic pool derived from the admixture of autochthonous genes identified by MHC blocks, associated with those present in European, African and Asian individuals, the proportion of which varies in the major urban city of Mexico.

Keywords : Immunogenetics; HLA; admixture estimates; HLA haplotypes.