NEW DNA POLYMORPHISMS DEFINE ETHNICALLY DISTINCT HAPLOTYPES IN THE HUMAN TRANSFERRIN RECEPTOR GENE

In a study of transferrin receptor (TFR) polymorphism in different eth nic groups using PCR and restriction cleavage we found a new Hin6I pol ymorphism in intron 7 and confirmed a tentative BanI polymorphism in e xon 4 reported by Evans and Kemp [Gene 1997;199:123-131], In all ethni c groups there was a complete and highly significant (p < 10(-10)) lin kage disequilibrium where all BanI 1 alleles were linked to Hin6I 1 al leles, Furthermore in the European populations, but not in the Chinese , there was a close correlation between the three BanI-Hin6I haplotype s and the alleles of a previously described three-allelic RsaI polymor phism in the TFR gene studied by Southern blotting, There were distinc t ethnic differences in TFR allele and haplotype frequencies, Thus the Saamis were significantly different from the other European ethnic gr oups, and the Lithuanians had a significantly increased frequency of t he BanI 2-Hin6I 1 haplotype, suggesting that this marker may be inform ative in tracing prehistoric migrations and admixture by Baltic people s, The new TFR polymorphisms and haplotypes may also be useful markers in studies of interactions with the transferrin and hemochromatosis g enes, the genetic influence on body iron stores and disease associatio ns.