BLOOD-GROUP CHARACTERISTICS OF THE CONTEMPORARY BULGARIAN POPULATION FROM MIDDDLE MIZIA

In this investigation we studied the blood group affiliation of the Bulgarian population from Middle Mizia according to the ABO systems and Rhesus factor in connection with the complicated ethnos of the Bulgarians. The sample comprised 769 individuals of both sexes. The defined distribution of the groups from the ABO system was established in the studied population. The comparison with a control group from the Bulgarian population was made. The following differences were established – a decreased presence of the blood group A and an increasing of the blood group B and of the blood group AB The differences by the blood group A are significant. There are no differences by the Rhesus factor. According to the group from Troyan, however, the data shows a presence of a mongoloid admixture. A significant decreasing of the blood group A was observed and weak presence of the negative Resus factor.


Introduction
The investigation of the blood group system is of big meaning for building up of fuller anthropological characteristic of a given population.Such attitude and Markovich (1994).Similar investigations in our country take up a particular place because of the complex ethnos of the Bulgarian people.In the investigations, carried out in our country up to now, the systems ABO and Rhesus factor are traced above all.The published results, up to now, of these investigations can be divided into of four groups by themes (subjects): 1. Regional investigationsat these examinations search eventual differences in the distribution of the separate groups (Todorov i sar. 1996(Todorov i sar. ,1997;;Todorov et al. 2009;Minkov i sar. 2004).

Material and methods
In this investigation are studied 769 individuals (382 men and 437 women) from the following towns of Middle Mizia -Veliko Tarnovo, Gorna Oriachovitsa and Troyan.It was traced a blood group belonging of the systems ABO and Rhesus factor.In this study are used standard tests of serums.For this purpose the study was accomplished according to the cross method.It was accomplished a comparison of the received results with these one of the control group from the Bulgarian population.(1080 persons).It was realized by means of T-criterion according to formula offered from (Markovich, 1985).The results are presented on table 1-4.

Results
Blood group system ABO.The received results are presented in table 1.At the examined excerpt was established the next distribution of the groups from the system: O group -31,99%, A group -32,12%, B group -23,15% and AB group -12,74%.It was established the characteristic for Bulgarians arrangement of the separate groups A, O, B, AB.At comparison of the indexes of the relative share by means of T-criterion, accomplished with control group, was established a bigger frequency of the cases with B group (23,15% to 18,04%), a little higher frequency at group AB (12,74% to 7,59%) and practically the some values at O group (31,99% to 31,67%).It is obvious the smaller frequency of the persons with A group toward this one at the control group (31,12% to 43,70%).The established difference is statistically significant (T=3,04, p<0,01).some increasing of O and AB groups (respectively with 3,83% and 4,91%).The decreasing of the percentage at the persons with A group is significant (with 28,20%, T=3,09, p<0,01).
The differences between the whole embraced contingent and the control are established and at comparison of their gene frequency.Particularly big is the difference at gene "p", more little at "r" and the most little at "q".

Discussion
The results of the distribution of the blood groups from the system ABO at the examined contingent distinguishes from the normal distribution of the traits at the Bulgarians as a whole.It makes an impression the considerable increasing of the percentage frequency of the group B. This phenomenon together with some increasing at AB and a significant decreasing of the percentages at group A, give us a reason to suppose, that in the Bulgarian ethnos from this region, are taken part and "eastern" elements.A special attention must pay to the group from Troyan.The arrangement of the separate groups (A, B, O, AB) distinguishes as from this one of the most Balcan populations, so and of the Bulgarians, generally.The big percentage at group B, the weak representation of group A and of the negative Rhesus factor shows , that in this region outline a presence of considerable " eastern" admixtures.
Our conclusion for a presence of "eastern" admixtures confirms and from more early leaded odontological investigations in the region of Troyan.(Minkov T, 1976) establishes an increased percentage frequency of shovel-shaped upper medial incisors (33%) in the studied population from this region.This is an indication for a presence of "eastern" admixture in the ethnos of the studied population.It is known that at the europoid population the percentage of the showel-shapeness of the incisors in the limits between 125 and 15%.

Conclusion
1.The studied population by the blood group traits characterize like a europoid population, but with a presence of "eastern" elements in its ethnos.
2. The excerpt from the region of Troyan distinguishes with considerably "eastern" admixture by the studied traits, that confirm as historical and other investigation in this region.

Table 1 .
A frequency of the blood groups in the population from Middle Mizia and from the

Table 2 .
A frequency of the blood groups and Rh factor in the population from Troyan Tabela 2. Distribucija krvnih grupa sistemima ABO i Rezus faktora na uzorku iz Trojana

Table 3 .
Gen frequency of the population in the studied groups Blood group system Resus factor.The results are presented in table 4. At the studied contingent is established a frequency of positive Rhesus factor of 84,65%, and of the negative -15,35%.At comparison with the control group were established identically values(respectively 84,65% and 84,81% and 15,35% and 15,19%).At the excerpt from town Troyan are established a significant increasing of the positive Rhesus factor (91,00% -t=2,35, p<0,02).

Table 4 .
A frequency of Rh factor the population from Middle Mizia and from the control group Tabela 4. Distribucija krvnih grupa sistema Rezus faktora na uzorku iz Srednje Mizije i kontrole