Origin of Mexican Nahuas (Aztecs) according to HLA genes and their relationships with worldwide populations.

Abstract A Nahua Aztec isolated group from Morelos State (Mexico) was studied for their HLA profile. The relationship with other Amerindians and worldwide populations was studied by using 13,818 chromosomes and calculating Nei's chord genetic distances (DA), neighbor-joining dendrograms and correspondence multidimensional values. Three new HLA extended haplotypes were found in our group: A * 30–B * 49–DRB1 * 1001–DQB1 * 0501 (the most frequent one in this population), A * 02–B * 52–DRB1 * 1402–DQB1 * 0301 and A * 68–B * 61–DRB1 * 1602–DQB1 * 0303. Both genetic distances and correspondence analyses clearly show that our Nahua isolated group is genetically close to some of the most ancient groups living in Mexico (Mayans, Zapotecans, Mixtecans). This suggests that Nahua language (Nahuatl) may have been imposed to scattered groups throughout Mexico; otherwise Aztecs may have been living in Mexico long before their postulated immigration in the XII century AD.