Serological and molecular analysis of HLA class I, class II and MICA allele and haplotype frequencies, and NK KIR gene profiles in the Thais of mainland south-east Asia

Abstract

There are some 70 million ethnic Thais residing in Thailand and neighbouring countries in mainland SE Asia, which makes the Thais one of the dominant ethnic groups in this region. Collecting large numbers of individuals (>500) from different regions of Thailand, we have analysed HLA-A, B, DR, DQ and DP allele frequencies in northern, north-eastern and central Thailand (Hum. Immunol. 40:20-24, 1994 & 53:174-82, 1997). We have detected north-south gradients or clades of DPB1 and DRB1 allele frequencies in our study populations, that may represent environmentally-driven selective pressures on these gene loci. Similarly, we have also deduced the composition and frequency of DRB1, DRB3, DRB5, DQA1 and DQB1 alleles present in DR51-, DR52- and DR53 related haplotypes and found north-south clades of haplotype frequencies (Hum. Immunol. in press, 2000). One class II haplotype DRB1*1502, DRB5*0102, DQA1*0101/4, DQB1*0501, would appear to be particularly characteristic of Thai populations. Using a recently developed MICA PCR-SSP typing scheme (Tissue Antigens 53:167-74,1999), together with the maximum likelihood method developed for analysing population data in the 11thIHWS, we have been able to deduce the composition and frequency of HLA-A, B, DR, DQ and MICA haplotypes in these populations. Finally, using PCR-SSP typing we have also determined NK KIR gene profiles in the Thais (Immunogenetics, in press, 2000). Taken together, our analyses will contribute to the expanding organ transplantation programs in this region, and provide an important data base for numerous disease association studies currently focused on these populations. © 2001 Blackwell Science Ltd,.