Allelic distribution of HLA class I genes in the Tibetan ethnic population of China

Abstract

Tibetans live in Qinghai-Tibet Plateau rising about 4000 m a.s.l. in south-west China. Archaeological evidences suggested that there have been humans living in Tibet at least 5000 years ago. However, Tibetan earlier history remains elusive. In the present study, allelic distribution of human leucocyte antigen (HLA)-A, -B and -Cw in 158 unrelated Tibetan Chinese was investigated using sequencing-based typing methods, and a total of 25 HLA-A, 45 HLA-B and 20 HLA-Cw alleles were identified. A*24G1 (27.2%), B*51G1 (16.8%), Cw*04G1 (13.3%) and Cw*070201G1 (13.3%) are the most common HLA-A, -B and -Cw alleles. The most frequently detected haplotypes were A*24G1-B*51G1-Cw*140201 (3.6%), A*24G1-B*51G1 (6.8%), A*02G1-Cw*070201G1 (6.5%) and B*51G1-Cw*140201 (5.0%). Chi-squared test suggested that all three loci fitted the Hardy-Weinberg expectations. No evidence for a departure from selective neutrality at the HLA-A and -B loci was observed. However, significant departure of the observed homozygosity from the expected values was found for HLA-Cw. Though the contemporary Tibetans inhabit the south-west China, Nei's genetic distance measure based on frequencies of HLA-A, -B and -Cw indicated that Tibetans were closer to northern Han Chinese, Mongolian Chinese, Koreans and Japanese rather than to southern Han Chinese. The corresponding dendrogram constructed according to the neighbour-joining method supported that Tibetans separated from southern Han and located in North-East Asian cluster which included northern Han Chinese and Mongolian Chinese. These data were in good agreement with language classification and with a recent hypothesis that Tibetan might originate from northern China along Yellow river.

Allele Polymorphism and Haplotype Diversity of HLA-A, -B and -DRB1 Loci in Sequence-Based Typing for Chinese Uyghur Ethnic Group

“…The neighboring ethnic groups used in the phylogenetic tree construction were Miao, Bouyei and Shui ethnic minorities [6], Jinuo and Wa populations [18], Maonan people [19], Yi ethnic minority [13], Tujia nationality [20], Dai population [21], Tibetan ethnic population [22], Mongolian and Hui ethnic groups [23], Kirgiz and Xibe ethnic minority (http://202.117.24.55:8001/xwlw/detail_xwlw.jsp?searchword_AUTHOR%3D%C9%F2%B4%BA%C3%B7&singlesearch_no&channelid_65004&record_2), Hong Kong Chinese population[24], Han from Southern China[25], Han population in Northern China [26], Taiwanese [27], Singapore Chinese [28], Javanese [29], Vietnamese population(the Kinh population in Vietnam)[30], Korean population [31] and Japanese population [32]. The three main clusters of populations obtained are: (1) the populations living in Korea, Japan and the northwestern of China, (2) the Han populations in different regions, and (3) the populations living in Vietnam, Indonesia and the southeastern of China.…”

“…The five alleles accounted for 54.81% of the total HLA-A allelic frequency. HLA-A*1101 is also the most common HLA-A allele in other populations such as Chinese Wa (58.4%) [18], Dai (39.1%) [21], Jinuo (36.7%) [18], Miao (35.9%) [6], Maonan (35.2%) [19], Bouyi (31.4%) [6], Shui (29.5%) [6], Yi (26.3%) [13], Drung (19.8%) [38], Uygur (19.7%) [14], Mongolian (16.2%) [23], Hui (15.9%) [23], Tujia (14.7%) [20], Tibetan (13.0%) [22], isolated Han population in Southwest China (31.7%) [39], Meizhou Han (30.3%) [40], Hong Kong Chinese population (28.7%) [24], Taiwanese (27.5%) [27], Han from Southern China (26.7%) [25], Beijing Han (20.23%) [37], Kinh population in Vietnam (22.9%) [30], Sundanese–Javanese (Indonesia) (16.42%) [29], Javanese (13.89%) [29], Korean (10.8%) [31], Xibe (8.54%), Japanese (8.2%) [32], Kirgiz (6.99%), the population on Madeira Island (Portugal) (5.9%) [41], German (5.06%) [42], Eastern European Americans (6.3%) [43] and Mexican Americans (4.2%) [44]. The HLA-A*1101 allelic frequency of Han population in the south of China is higher than those of Han population in the north of China, Japanese and Korean.…”

Geographical and Ethnic Distribution of the HBV C/D Recombinant on the Qinghai-Tibet Plateau

“…Study from hepatitis C virus has shown that adaptation to multiple host Human leukocyte antigen (HLA) alleles is an important cause of viral mutation and evolution, and thus divergence [35]. Previous investigations have shown the great polymorphism of HLA alleles among the Tibetan, Uygur, and Han populations in western China [36], [37]. In particular, although the Tibetan and northern Han Chinese populations shared many similar HLA alleles, they also had distinct frequencies of many HLA alleles and haplotypes.…”

Human leukocyte antigen class I polymorphism in Miao, Bouyei, and Shui ethnic minorities of Guizhou, China

“…The high diversity of HLA alleles and haplotypes make HLA a very useful genetic marker for anthropologic studies and disease association. The polymorphism of HLA class II genes in Chinese populations has been intensively investigated, but only a few high-resolution data on polymorphism of HLA class I genes in Chinese populations are available so far [1][2][3][4]. In the present study we investigate the allelic distribution of the HLA-A, -B, and -C genes in the Miao, Bouyei, and Shui ethnic minorities in Guizhou, southwest China using sequencing-based typing (SBT) approaches in order to expand our knowledge of HLA polymorphism in Chinese ethnic groups and further the understanding of Chinese ethnic relationships and genetic predisposition to diseases.…”