The haplotypes of 97 beta(A) independent chromosomes from a Mexican Huichol Native American group were analyzed. The analysis also included 87 beta(A) chromosomes from a Mexican Mestizo population previously studied. Among Huichols, eight different 5' beta haplotypes (5Hps) were observed, with types 1(+ - - - -), 13(+ + + - +) and 2(- + + - +) at frequencies of 0.794, 0.093, and 0.041, respectively. In Mestizos, 17 5Hps were found, types 1, 3(- + - + +), 2, 5(- + - - +) and 9(- - - - -) being the most common at frequencies of 0.391, 0.172, 0.092, 0.069, and 0.046, respectively. 3' haplotype (3Hps) frequency distributions were 0.443(+ +), 0.083(+ -), and 0.474(- +) in Huichols and 0.563(+ +), 0.149(+ -), and 0.287(- +) in Mestizos. Pairwise comparison for both haplotype distributions between the two populations showed significant differences. Pairwise distributions of 3Hps for Huichols were compared with nine worldwide populations, three African, two Asian, two Melanesian, one Caucasian, and one United States Native American. The distributions of the Huichol were different (P < 0.05) from all populations except the Native American. Nei's genetic distances showed the Huichols to be closer to the Native Americans, followed by Melanesians from Vanuatu and Asians; Africans were the farthest. The 5Hp distributions in Mexicans were also compared with 23 worldwide populations (including African, Native American, Asian, Caucasian, and Pacific Islanders). Huichol distributions were different (P < 0.05) from all other populations except Koreans. The Mestizo distribution was also different from the others, except three Caucasian groups. Nei's genetic distance between the same populations disclosed that the Huichols are in relatively close proximity to five out of six Asian populations considered. The same analysis with grouped worldwide populations showed Native Americans as population closest to the Huichols, followed by Pacific Islanders and Asians. Present observations are consistent with an important Asian contribution to the Huichol genome in this chromosomal region. Am. J. Hum. Biol. 12:201-206, 2000. Copyright 2000 Wiley-Liss, Inc.