HIGH-RESOLUTION CHARACTERIZATION OF HLA CLASS I AND CLASS II DIVERSITY IN SARASWAT BRAHMIN AND SINDHI POPULATIONS OF JAIPUR, RAJASTHAN

Abstract

Background: The human leukocyte antigen (HLA) system is one of the most genetically varied segments of the human genome and plays a pivotal role in the regulation of the immune system, susceptibility to diseases, and success of hematopoietic stem cell or solid organ transplantation. Given the pronounced genetic diversity within the Indian population, acquiring high-resolution, population-specific HLA data is crucial.

Methods: High-resolution next-generation sequencing based HLA typing was performed for six classical loci (HLA-A, -B, -C, -DRB1, -DQB1, and -DPB1) in 296 healthy, unrelated individuals from two North Indian populations: Saraswat Brahmins (n = 148) and Sindhis (n = 148). Allele and haplotype frequencies, Hardy-Weinberg equilibrium (HWE), linkage disequilibrium (LD), and haplotypic associations were analyzed using established statistical methods.

Results: Extensive allelic diversity was observed across all loci in both populations, with HLA-B being the most polymorphic. High heterozygosity was maintained across class I and class II loci, whereas HLA-DPB1 showed comparatively higher homozygosity. A strong and consistent LD was observed between HLA-DRB1 and HLA-DQB1 in both populations of this study. Population-specific enrichment of alleles and haplotypes was evident, particularly for HLA-B and HLA-DPB1 genes. The Sindhi population demonstrated greater HLA-DPB1 allelic diversity, whereas the Saraswat Brahmin population showed stronger overall haplotypic conservation than the Sindhi population.

Conclusion: This study provides comprehensive four-field resolution HLA data for two distinct North Indian populations, highlighting both had population-specific genetic structures. These findings are relevant to transplantation immunogenetics, donor registry optimization, and population genetics research in India.