Studies on the human immunoglobulin allotypes in five populations in the USSR.

Serum samples obtained from a total of 664 individuals representing five populations (Koryaks, Northern Buriats, Southern Buriats, Mongols and Uralians) in the USSR were tested for Glm(a,z,x and f) and G3m(b0,b1,b3,b4,b5,s,t,g and u), and Km(l) allotypes. According to Gm patterns, the first four of these populations are characterized by the presence of four haplotypes, namely Gm a,z;g,u, Gm a,z,x;g,u, Gm a,z;b0,b3, b5,s,t and Gm a,f;b0,b1,b3,b4,b5,u which are characteristic of Mongoloid populations, whereas the Uralian population is characterized by three haplotypes, Gm a,z;g,u, Gm a,z,x;g,u, and Gm f;b0,b1,b3,b4,b5,u which are common to Caucasoids as well as the Gm a,z;b0,b3,b5,s,t haplotype typical of northern Mongoloid populations. Results obtained from the four Mongoloid populations in Siberia indicate clear genocline, extending from Kamchatka to Mongol in which the haplotype frequency of Gm a,z;g,u changes from 0.714 to 0.431 and that of the Gm a,f;b0,b1,b3,b4,b5,u haplotype from 0.031 to 0.231. On the other hand, the Gm a,z;b0,b3,b5,s,t haplotype is found in the highest incidence (0.307) among Buriats from north Baikal, a population considered to have the most prominent Mongoloid characters, and indicates a cline from the Baikal to east and to south. In contrast to the Gm system, no significant regional differences in the frequencies of the Km1 allele were observed among these different populations.