We have been studying polymorphisms of HLA class I and II genes in East Asians including
Buryat in Siberia, Mongolian, Han Chinese, Man Chinese, Korean Chinese, South Korean,
and Taiwan indigenous populations in collaboration with many Asian scientists. Regional
populations in Japan, Hondo-Japanese, Ryukyuan, and Ainu, were also studied. HLA-A,
-B, and -DRB1 gene frequencies were subjected to the correspondence analysis and calculation
of DA distances. The correspondence analysis demonstrated several major clusters of
human populations in the world. "Mongoloid" populations were highly diversified, in
which several clusters such as Northeast Asians, Southeast Asians, Oceanians, and
Native Americans were observed. Interestingly, an indigenous population in North Japan,
Ainu, was placed relatively close to Native Americans in the correspondence analysis.
Distribution of particular HLA-A, -B, -DRB1 alleles and haplotypes was also analyzed
in relation to migration and dispersal routes of ancestral populations. A number of
alleles and haplotypes showed characteristic patterns of regional distribution. For
example, B39-HR5-DQ7 (B*3901-DRB1*1406-DQB1*0301) was shared by Ainu and Native Americans.
A24-Cw8-B48 was commonly observed in Taiwan indigenous populations, Maori in New Zealand,
Orochon in Northeast China, Inuit, and Tlingit. These findings further support the
genetic link between East Asians and Native Americans. We have proposed that various
ancestral populations in East Asia, marked by different HLA haplotypes, had migrated
and dispersed through multiple routes. Moreover, relatively small genetic distances
and the sharing of several HLA haplotypes between Ainu and Native Americans suggest
that these populations are descendants of some Upper Paleolithic populations of East
Asia.