Polymorphism and distribution of HLA-DR2 alleles in Mexican populations.
DRB1*15/16 nucleotide polymorphism was analyzed in 68 DR2 positive individuals (18 Mexican Mestizos, 30 Mazatecans and 20 Nahuas), carrying a total of 75 DR2 haplotypes. HLA-DR2 was one of the most frequent specificities detected in Mazatecans and Nahuas with gene frequency (gf) of 0.232 and 0.141, respectively. In these populations DRB1*16 was the most frequent DR2 split (gf = 0.183 in Mazatecans and gf = 0.135 in Nahuas), whereas in Mexican Mestizos the most frequent was DRB1*15 (gf = 0.065). Four DRB1-DQB1 combinations in Mexican Mestizos, two in Mazatecans and one in Nahuas were in linkage disequilibrium. In spite of the restricted polymorphism, there were differences on DRB1*15/16 alleles found in Mexicans. DRB1*1501 a Caucasian allele was predominant in Mexican Mestizos, whereas DRB1*1602 an Amerindian allele was characteristic on Indian populations. An important difference was detected among the Amerindian populations studied since DRB1*1502 was only present in Mazatecans. This data corroborates the restricted polymorphism of DRB1*15/16 and the high frequency of DRB1*16 subtype in autochthonous American populations and suggest that the differences in gene frequencies of DRB1*15/16 alleles could be helpful in distinguishing each of these population.
Cellular Biology Section, Physiology Department, Instituto Nacional de la Nutrición Salvador Zubirán, D.F., Mexico, Mexico. gvargas63@yahoo.com
G
G
Vargas-Alarcón
G
G
Hernández-Pacheco
R
R
Gamboa
J
J
Zuñiga
C
C
Flores
E
E
Gomez-Casado
J
J
Martínez-Laso
J
J
Granados
A
A
Arnaiz-Villena
D000483:Alleles; D005006:Ethnicity; D006683:HLA-DQ Antigens / Q000235:genetics; D059866:HLA-DQ beta-Chains; D006684:HLA-DR Antigens / Q000235:genetics; D059810:HLA-DR Serological Subtypes; D015802:HLA-DR2 Antigen / Q000235:genetics*; D059811:HLA-DRB1 Chains; D006801:Humans; D008800:Mexico / Q000208:ethnology; D011110:Polymorphism, Genetic
D006683:HLA-DQ Antigens; D059866:HLA-DQ beta-Chains; C069051:HLA-DQB1 antigen; D006684:HLA-DR Antigens; D059810:HLA-DR Serological Subtypes; C106559:HLA-DR15 antigen; C067266:HLA-DR16 antigen; D015802:HLA-DR2 Antigen; D059811:HLA-DRB1 Chains