P8.039: Allele, Genotype and Haplotype Frequencies of the HLA System in the Province of Neuquén, Argentina

Abstract

Knowledge of the bioanthropological and genetic characteristics of the population in Neuquén is limited. Determination of the allele and haplotype frequencies of the HLA system provides data on genetic variability, susceptibility or resistance to diverse disease, immunological phenomena and contributes to the selection of donors and recipients in organ transplantation. 583 samples from patients attending the histocompatibility laboratory between January 2015 and March 2022 have been analyzed retrospectively. HLA typing of locus A, B and DR has been performed on all patients by using medium resolution ssop methodology (sequence specific oligonucleotide probes). It was observed that, in locus A, the predominant allele was A2, with a frequency of 15.5 (42.8%). It was followed by A68, with a frequency of 12.22 (33.2%) and A24, with a frequency of 6.83 (20.8%). In locus B, the majority alleles were B35 and B39, with a frequency of 2.68 (33.3%). They were followed by B7, with a frequency of 2.89 (13.8%) and B40, with a frequency of 2.68 (12.8%). In locus DR, the most frequent allele was DR4, with a frequency of 20.85 (46,5%). The second most frequent allele was DR11, with 9.23 (20.6%), and finally, DR8, with 9.0 (20%). The most frequent genotype in locus A was A2-A68 (9.77%). In locus B, it was B35-B39 (5.83%) and, in locus DR, it was DR4-DR4 (7.55%). The most frequent haplotypes were A2-B39 (15%) and A68-B39 (13,4%). Regarding loci A-B-DR, the most observed haplotype was A68-B39-DR4 (7.5%). Due to the existing demographic growth in the province, according to the last census, Neuquén received population from the whole country (Argentina) and from South American countries. Even though the most frequent alleles were similar to alleles from other studies conducted, substantial discrepancies were also identified. Thus, considering the great number of native peoples present in Neuquén, using these methodologies for the study of closed populations would be convenient in the future. Baradello Stefano.