[Effect of interbreeding on the variability of anthropometric traits at birth and the variability of polymorphic...

Effects of outbreeding on variation of four anthropometric traits--body weight, body length, and circumferences of head and chest--and variability of seven polymorphic loci coding for blood proteins--HP, GC, PGD, GLO1, ESD, ACP, and PGM1--were studied. A total of 514 infants (271 boys and 243 girls) were examined. On the basis of pedigree analysis, two groups were formed: infants from monoethnic families (N = 363) and those from multiethnic backgrounds (N = 151). The two groups did not differ significantly with respect to the mean values and variances of the four anthropometric traits, but the coefficients of correlation between the traits among outbred newborns were higher than those for newborns from monoethnic families. The heterozygosity of the offspring of interethnic marriages was insignificantly higher than that of purely Russian infants. However, the linkage disequilibrium calculated for all possible pairwise combinations from the seven polymorphic loci was substantially higher in the offspring of interethnic marriages. The data obtained confirmed an earlier suggestion that outbreeding enhanced epistatic gene interaction in human populations.