1. HLA-DRB1* and DQB1* allele and haplotype diversity in eight tribal populations: Global affinities and genetic basis of diseases in South India.
- Author
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Rangasamy, Nandakumar, Chinniah, Rathika, Ravi, Padma-Malini, Vijayan, Murali, Sivanadham, Ramgopal, K.V., Darsa, Pandi, Sasiharan, Sevak, Vandit, Krishnan, Prabhakaran, and Karuppiah, Balakrishnan
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ALLELES , *IMMUNOGENETICS , *HAPLOTYPES , *GENETIC disorders , *INDIANS (Asians) , *DNA fingerprinting - Abstract
The distribution of HLA class-II DRB1* and DQB1* alleles/ haplotypes were studied in 438 individuals of 8 Dravidian tribal groups inhabiting the Western Ghats, south India. The HLA typing was performed by PCR-SSP method. In order to identify the 5-locus Ancestral Extended Haplotypes (AEH), the alleles of HLA-A, -B and -C loci were typed for DNAs with predominant 2-locus haplotypes. The analyses have revealed allele HLA-DRB1*15 as the most predominant allele (Lowest / Highest range: Urali, 14.81 / Malasar, 48.94), followed by the alleles DRB1*10 (Katunayakan, 1.85 / Paliyan, 48.21), DRB1*14 (Paliyan 4.46 / Katunayakan, 40.74), DRB1*12 (Mannan, 1.64 / Katunayakan, 20.37) and DRB1*03 (Mannan, 1.64 / Urali, 29.63). The most frequent DQB1* alleles were DQB1*02 (Paliyan 3.57 / Urali, 23.15), DQB1*05 (Katunayakan, 27.77 / Paliyan 84.82) and DQB1*06 (Malasar, 8.51 / Kuruman, 33.51). The most predominant two-locus haplotypes observed were DRB1*15-DQB1*05, DRB1*10-DQB1*05, DRB1*15-DQB1*06 and DRB1*04-DQB1*05. The present study of HLA immunogenetics of south Indian tribes have revealed the presence of globally shared two and 5-locus haplotypes. Many of these haplotypes were implicated in a number of diseases in south India. We observed the presence of ancestral extended haplotypes (AEHs), hitherto not reported in Indian populations such as, A*68-B*35-C*02-DRB1*15:01-DQB1*05:01, A*24-B*57-C*06-DRB1*04:01-DQB1*05:01 and A*24-B*35-C*02-DRB1*15:01-DQB1*05:02. The dendrogram based phylogenetic analyses have revealed the Caucasian affinity of Urali, palaeo-Mediterranean and Indo-European affinity of Malasar tribes. The presence of globally shared susceptible and protective haplotypes reiterated the mosaic immunogenetic fabric of south Indian tribes. • Alleles HLA-DRB1*15, DRB1*10, DRB1*14, DQB1*05 and DQB1*06 revealed increased frequencies. • Two locus haplotypes DRB1*15-DQB1*05, DRB1*10-DQB1*05 and DRB1*15-DQB1*06 were predominant. • Lower frequencies of Caucasian alleles HLA-DRB1*07 and DQB1*03:02 and two-locus haplotype DRB1*07-DQB1*02 were observed. • Five-locus extended haplotypes raises interesting evolutionary insight of south Indian tribes. • Phylogenetic analyses revealed Urali with Caucasoid and Malasar with palaeo-Mediterranean and Indo-European affinities. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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