Allele and Haplotype Frequencies of Human Leukocyte Antigen-A, -B, and -DR Loci in Koreans: DNA Typing of 1,500 Cord Blood Units / 대한진단검사의학회지

BACKGROUND: The HLA system is known to be the most polymorphic genetic system in human, and HLA allele and haplotype distribution varies widely among different ethnic groups. This study was performed to examine the frequencies of HLA alleles and haplotypes in Koreans. METHODS: We examined HLA-A, -B, and -DR alleles at the serologic level in 1,500 cord blood units obtained from Koreans using the PCR-sequence specific oligonucleotide (SSO) method. Allele and haplotype frequencies were estimated by the maximum likelihood method using the computer program developed for the 11th International Histocompatibility Workshop. RESULTS: HLA alleles found in Koreans were 12 in A, 31 in B, and 13 in DR loci. Most frequent alleles with frequencies > or =10% in each locus in decreasing order of frequency were: A2, A24, A33, A11; B62; DR4, DR15, DR9, and DR13. Two-locus haplotypes with frequencies > or =0.1% were 104 A-B and 115 B-DR haplotypes, among which those with frequencies > or =1.0% showing significant positive linkage disequilibrium (P or =0.1% were identified. The results were similar to those of a previous study in 1,600 Koreans, although some differences were noted in the distribution of some less frequent alleles or haplotypes with frequencies < or =0.5%. CONCLUSIONS: We provided the allele and haplotype frequencies of HLA-A, -B, and -DR in cord blood units of Korean ethnicity defined by a DNA typing method, which can be used as basic data on Koreans for organ transplantation and disease association studies.

A*02 in southern Thai Muslims and central Thais.

The HLA-A*02 subtyping in Thais was conducted and included in the 12th International Histocompatibility Workshop (12WS). A total of 81 randomized individuals previously serologically or DNA typed as A2 were studied for A2 subtypings. The subjects consisted of 32 Southern Thai-Muslims (STM) and 49 Central Thais (CT). The 12WS HLA-A*02 subtyping DNA typing kit was employed. The most common A*02 subtypes in STM were A*0203,*0201 and *0207 while they were A*0203, *0207 and *0201 in CT. A*0202, *0204, *0208, *0209, *0212, *0213, *0214, *0215, *0216 and *0217 were not found in both STM and CT. The 12WS data indicated that A*0201 was also the most frequent allele of A*2 among North-East Asians. A2 subtype study in 32 STM revealed that 2 in 8 of A*0201 showed the absence of bands at 813 bp and 705 bp with primer mix number 03A and 517A and weak reaction band with primer mix number 33A. In addition, 3 subjects with A*0201 variations have one nucleotide difference in exon 2 by sequence base typing (by MGJ. Tilanus) which will be reported separately. CONCLUSION: More variations of A*02 were observed among STM compared to CT. The variations of reactions with the set of primer mix should be carefully observed and subjected to further analysis.