Transferrin variants as markers of migrations and admixture between populations in the Baltic Sea region.

Transferrin (TF) types were examined by isoelectric focusing in an attempt to elucidate migrations and admixture between populations in the Baltic Sea region. A highly significant heterogeneity between populations was found with respect to TFC subtypes as well as the rare TF variants B2, B0-1 and DCHI. With the exception for Estonia, increased frequencies of the TFC3 allele were observed east of the Baltic Sea. The island of Gotland in the middle of the Baltic Sea also showed a high TFC3 frequency indicating an eastern influence. The TFDCHI allele, a marker of eastern (Finno-Ugric) influence, was found in Finland and Estonia and on the island of Gotland, but not in mainland Sweden and in the Baltic peoples (Latvians and Lithuanians). These results indicate the presence of a Finno-Ugric, most likely Estonian or Livonian, genetic influence in the Gotland population.