Distribution of plasma alpha-1-B-glycoprotein phenotypes in several Mongoloid populations of East Asia.

The distribution of plasma alpha 1B-glycoprotein (alpha 1B) phenotypes was determined by a simple method of two-dimensional electrophoresis followed by protein staining in a group of 1,154 individuals from 8 Mongoloid populations of East Asia. The sample comprised 581 Chinese from different localities (Singapore: 204; Taiwan: 150; Fujien and Hopeh provinces of eastern China: 146 and 81), 155 Koreans, 155 Filipinos, 152 Thais and 111 Malays. Altogether, 6 different alpha 1B phenotypes (1-1, 1-2, 2-2, 1-3, 2-3, and 1-6) were observed. The alpha 1B allele frequencies were very similar in all of the populations. The frequency of A1B1 varied from 0.89 to 0.91 and that of A1B2 from 0.08 to 0.10. The A1B3 allele, reported previously only in American blacks, was observed with a frequency range of 0.003-0.01 in 3 of the Chinese populations, in Koreans and in Malays. A new alpha 1B allele (A1B6) was observed in 2 Chinese individuals.