HLA Allele and Haplotype Frequencies in Three Urban Mexican Populations: Genetic Diversity for the Approach of Genomic Medicine

Abstract

Genetic variability defends us against pathogen-driven antigens; human leucocyte antigens (HLA) is the immunological system in charge of this work. The Mexican mestizo population arises mainly from the mixture of three founder populations; Amerindian, Spaniards, and a smaller proportion of the African population. We describe allele and haplotype frequencies of HLA class I (-A and -B) and class II (-DRB1 and -DQB1), which were analyzed by PCR-SSP in Mexican mestizo from three urban populations of Mexico: Chihuahua-Chihuahua City (n = 88), Mexico City-Tlalpan (n = 330), and Veracruz-Xalapa (n = 84). The variability of the allele HLA class I and class II among the three regions of Mexico are in four alleles: HLA-A*24:02 (36.39%), -B*35:01 (16.04%), -DRB1*04:07 (17.33%), and -DQB1*03:02 (31.47%), these alleles have been previously described in some indigenous populations. We identified 5 haplotypes with a frequency >1%: HLA-A*02:01-B*35:01-DRB1*08:02-DQB1*04:02, A*68:01-B*39:01-DRB1*08:02-DQB1*04:02, A*02:01-B*35:01-DRB1*04:07-DQB1*03:02, A*68:01-B*39:01-DRB1*04:07-DQB1*03:02, and A*01:01-B*08:01-DRB1*03:01-DQB1*02:01. Also, the haplotype A*02:01-B*35:01-DRB1*08:02-DQB1*04:02 was identified in Tlalpan and Xalapa regions. Haplotype A*01:01-B*08:01-DRB1*03:01-DQB1*02:01 was found only in Tlalpan and Chihuahua. In the Xalapa region, the most frequent haplotype was A*24:02-B*35:01-DRB1*04:07-DQB1*03:02. These alleles and haplotypes have been described in Amerindian populations. Our data are consistent with previous studies and contribute to the analysis of the variability in the Mexican population.

Role of the Host Genetic Susceptibility to 2009 Pandemic Influenza A H1N1

“…A relatively low frequency of the A*02:01:01-B*35:01:01-C*04:01:01 haplotype was observed among the A H1N1/09 patients. This specific HLA haplotype represents more than 2.5% in the control group and has been found only in Hispanic and Mexican populations [ 140 , 142 ] with the resolution employed in this study. An increase in the frequency of A*68:01:02-C*07:02:01 haplotype in the patients’ group was also observed, a relevant finding since linkage disequilibrium is very high in the region, rendering potential haplotypes and can potentially amplify the disease risk.…”

“…A*24 comprises a large portion of the world population; this allele family is more common in some indigenous groups and constitutes more than half of the global population, especially in Asian countries and several Native American populations [ 141 ]. There is variability in the A*24 frequencies in Mexican mestizos depending on the Amerindian contribution and the region studied [ 142 ]. In this study, only 8.33% of the patients had any allele of the A*24 serotype, whereas the contact subjects reach 18% (A*24:02:01) [ 135 ].…”

“…In this study, only 8.33% of the patients had any allele of the A*24 serotype, whereas the contact subjects reach 18% (A*24:02:01) [ 135 ]. The overall allele frequency of A*24:02 in Mexican mestizos is 16.4% [ 142 ]. Recently, a cross-HLA allele T cell response against the influenza A virus peptides were detected among both HLA-A11(+) and HLA-A24(+) donors.…”

<p>Heterozygous Genotype rs17580 AT (PiS) in <em>SERPINA1</em> is Associated with COPD Secondary to Biomass-Burning and Tobacco Smoking: A Case–Control and Populational Study</p>

“…These results lead us to the question about the frequency of risk alleles among Mexican people, in which ancestral contribution has been marked by an admixture between Caucasian and indigenous (Amerindian) populations. 34 Some populations have national registries for subjects carrying PiZ (homozygous) who, without being smokers develop COPD, such is the case of the Swedish registry where 28% of its non-smoking population undergoes from the disease. 35 Those who carry the PiZ allele commonly have a more significant decrease in lung function, and if they are smokers, a high probability of mortality compared to those who are not PiZ carriers.…”

The Polymorphism of HLA-A,-B,-C,-DRB1,-DQB1,-DRB3/4/5 loci in Zhejiang Han Population,China Using NGS Technology

“…Now NGS technology is increasingly used in HLA genotyping forhigh resolution [18][19][20][21][22][23][24][25][26][27],it has high throughput and can bedecreased the rate of the ambiguous allele combinations. Here weused a commercial NGS method for HLA genotyping.…”