Human chromosomal polymorphism. IV. Chromosomal Q polymorphism in Russians living in Kirghizia.

Chromosomal Q polymorphism was studied in 200 Russian individuals (94 females and 106 males) living in Kirghizia. Of the 200 individuals, 191 had chromosomal Q polymorphic variants, while nine (4.5%) had no Q bands with fluorescence levels 4 and 5. The mean number of Q variants per individual ranged from 0 to 7, with a mean of 2.9. There were no differences in the frequency of Q variants between sexes. The observed homo- and heteromorphic frequencies completely agreed with those predicted by the law of Hardy-Weinberg. Of the 200 individuals, 12 (6.0%) had pericentric inversion of the Q band in chromosome 3, one individual (0.5%) having a homomorphic form of this inversion. The possible selective value of chromosomal Q heterochromatin material in the adaptation of human populations to extreme environmental factors, in particular to cold, and the possible taxonomic value of inverted Q heterochromatin bands in chromosome 3 in ethnic anthropology, are discussed.