BLOOD GROUP TYPES IN GREEKS FROM MAGNISIA AND LARISSA DISTRICTS ( EASTERN THESSALY )

The study of the human ABO blood system is of high significance for the anthropological characterization of a population. For the aims of the present study there have been examined in view to ABO blood group system 237 individuals, as well as and 245 individuals according to Rh system – of both genders. The studied contingent represents a heterogeneous student group from eastern Thessaly Region, Central Greece. Among the sample blood group 0αβ showed the highest frequency 39,66% whereas most rare was AB (9.28 %). Gender differences regarding the frequency of blood groups 0 and A were also established. 86.93% of individuals have positive Rh factor. Rh positive is more frequent among women 90.08% , and Rh-negative in men (9.92%). The comparison of the obtained genetic frequencies with older data showed heterogeneity among local Greek populations in comparison with some more distant ones. Accumulation of further data is needed, in order to solve the questions arisen.


Introduction
The AB0 system was discovered in 1901, but since then many researchers are tried to find connections between blood group system and various aspects of anthropology and medicine (Maksimova et al., 2002;Maksimova et al., 2007;Timceva et al., 1998Timceva et al., -1999;;Todorov et al., 2004;Vizev et al., 1987); ethnicities, regions, races, population dynamics (Todorov et al., 1983;Todorov et al., 1991;Todorov et al., 1993;Todorov et al., 1996;Todorov et al., 1998Todorov et al., -1999;;Janeva et al., 2005;Torun et al., 2012;Özkasap et al., 2013;Nedjlaa 2013); life expectancy (Todorov 1981); paternity.The widespread use of serological systems makes them exactly relevant to the anthropological characteristics of a population (Bliznakov, Popvasilev, 1980).Although these characters have been well studied worldwide including Greece in total (Constantoulis, Paidousis, 1958;Xirotiris et al., 1980;Kremastinou, 1996;Lialiaris et al., 2011), or by administrative region (Paidousis, Krimbas 1980), there is no current information about the frequency distribution of the blood groups in this particular study area.Thanks to the contemporary human migration worldwide, as well as in the study area the native gene pool changes during time, and hence the frequency distribution of AB0 and Rh blood groups are also changing (Lialiaris et al., 2010).
The purpose of this study is to examine the genetic frequencies of blood groups AB0 and Rh system the native population of eastern Thessaly, as well as to compare them with nearby inhabiting groups on the basis of previous bibliographic sources.

Material and methods
The current study was conducted in eastern Thessaly -Central Greece (cities Volos, Larisa and adjacent villages).The population inhabiting the study area represents about 70% of that in Thessaly region.237 clinically healthy individuals of both genders (123 women and 114 men), as well as 245 individuals (131 women and 160 men) have been questioned about their blood group type and Rh-system respectively.The fact about every concrete blood group type was extracted from personal health books, preliminary tested in laboratory.The sample covers a diverse age group and has been studied in terms of their uncontamined origin up to three generations ago by questionnaire method.The genetic frequencies have been calculated from the experimental phenotypic AB0 types, under Hardy-Weinberg's law (1908).Differences between the experimental frequencies between male and female part of the examined sample have been estimated by the aims of Chi square test.The obtained results have been compared with the AB0 genetic frequencies of other populations, which inhabit nearby areas.Under this consequence, the examined group has been probably contemporary or during the past influenced by them.The divergence between the studied and other populations was estimated according to Nei, (1972).Visualization of the genetic distances between the populations has been accomplished according to Culman et al., 2009.

Results
The most frequent blood group type among the examined group occurred to be 0 αβ (39.66%), as opposed to AB (9.28%), which corresponds to the data of V. Todorov, 1986.Blood type A predominates among women, whereas 0 among men.Nevertheless, these differences according to gender are not statistically provable (к=3, х 2 =2.71 and р>0.05).
Тable 1. Established and expected genetic frequencies concerning the AB0 blood type system in inhabitants of eastern Thessaly region, central Greece.The expected and experimental genetic frequencies are almost the same, which is an indication for genetic equilibrium.p is also of lower frequency, compared to q.

Gender
In terms to Rhesus factor, 86% of the examined individuals are positive.More women have positive Rhesus factor, in comparison to men (90.08% and 82.46% respectively) and the opposite (table 2).These differences are not statistically significant (к=1, х 2 =3.03 and р>0.05).
Calculation of the theoretical and the observed genetic frequencies showed that they are approximately the same.The derived results concerning the frequency of Rhesus factor correspond to the specific for the total European population frequencies (Шаповалова, 1962).
Тable 2. Established and expected genetic frequencies concerning the Rh blood type system in inhabitants of eastern Thessaly region, central Greece.

Discussion
Similar expected and experimental genetic frequencies of Blood groups and Rhesus factor are indicator for a Hardy-Weinberg's equilibrium.This result derives from the fact of the sample's uncontamined origin.
In view to the established genetic frequencies of the AB0 blood groups system and compared with previous studies given in table 3, the examined sample is most divergent compared to the inhabitants of Odrin town (DNei=0.008)and most akin to these from Romania (DNei=0.001).When compared with the frequencies established before for Greek population in total (table 4), a slightly increased q on account of r is established, whereas p remains inside the range.
Table 3. Various groups compared to a population from Eastern Thessaly, central Greece on the basis of their of their AB0 blood groups genetic frequencies. The examined sample is of proved uncontamined origin.The data used for comparison from other sources are described from "inhabitants" of given area, but not "proved native population".

Volos+Larissa Eastern Thessaly -Greece V+L-GR current study
Nevertheless, if we accept that the heterogeneity of origin concerning some of the samples studied before is not affecting frequencies, heterogeneity of AB0 genetic frequencies among local groups in Greek territory cannot be excluded.AB0 system alone probably does not represent a good distinguishing genetic marker for some neighbor human populationsin this case a perquisite for Hardy-Weinberg's equilibrium is lacking: migration is constant in the region from about 4000 BC.
Accumulation of further data obtained on the basis of various genetic markers and other methods is needed in local scale, in order to solve the questions arisen.

Table 4 .
Genetic frequencies of AB0 Blood group system in Greece according to various sources and current study.

.
Nei's (1972)genetic distances calculated on the AB0 genetic frequencies between a studied population from eastern Thessaly region, central Greece, and nearby inhabiting groups.Abbreviations are given in table 3.