Distributions of HLA class I alleles and haplotypes in Bulgarians - contribution to understanding the origin of the population

In this study we present for the first time HLA class I allele and haplotyp e frequencies at DNA level in the Bulgarian population. HLA class I profile of Bulgarians has been compared to other European and Mediterranean popula tions of common historical background in order to clarify more precisely th e origin of our population. Genetic distances, phylogenetic trees and corre spondence analyses show that the Bulgarian population is more closely relat ed to the Italian, the Mediterranean, the Armenian and the Romanian populat ion than to the other East and West European population. This is further su pported by the analysis of HLA class I haplotypes in Bulgarians. Most of th em are also common in Europe. However their frequency pattern in Bulgarians is similar to the South European populations. The presence of some rare al leles and haplotypes indicated Asian genetic inflow. On the basis of HLA cl ass I profile and supported by historical and anthropological data, we sugg est that the Bulgarian population is characterized by the features of the S outhern European anthropological type with some influence of other groups s uch as Asians, Turks, Armenians. Migrations and assimilation of many differ ent ethnic groups are the major factor determining the genetic diversity of our population.