LINKAGE DISEQUILIBRIUM AT THE HUMAN PHOSPHOGLUCOMUTASE-1 LOCUS

By considering the four common PGM1 alleles as haplotypes, that is, co mbinations of mutations at two polymorphic intragenic sites (1/2 and A /B), we investigated the levels of linkage disequilibrium in 142 human population samples. These groups showed considerable diversity in the ir disequilibrium (D(rel)) and heterogeneity. In all the populations t he disequilibrium was found to be due to an excess of 1A and 2B haplot ypes, although this direction is the opposite of that expected accordi ng to the proposed phylogeny of the system. Natural selection could be one of the major causes for such a disequilibrium direction.