Presentation Abstract

Title: P16.012 - Frequency analysis of the CCR5-Delta32 allele in medieval and modern Romanian population
Keywords: CCR5-delta 32; ancient DNA; lethal epidemics
Authors: F. Raicu1,2, R. Cocos1, S. Schipor3, L. Bohiltea1;
1University of Medicine and Pharmacy, Bucharest, Romania, 2Institute of Anthropology "Francisc I. Rainer", Bucharest, Romania, 3"C.I. Parhon" Institute of Endocrinology, Bucharest, Romania.
Abstract: The CCR5-delta 32 mutation in human chemokine receptor gene can be considered a rare example of a beneficial mutation. The mutation gives its homozygous carriers complete resistance against HIV infection and has been proposed to provide protection against different lethal epidemics. Although the origin of the mutation indicates prehistoric times, repeated waves of lethal epidemics over medieval centuries strongly modified the European gene pool via bottleneck effect and seem to increase the frequency of CCR5-delta 32 up to 20% as a result of selective advantage.
In order to investigate if the lethal epidemics of the medieval times selected the allele we analyzed the presence of this mutation in aDNA isolated from the skeletons discovered in Pia[[unable to display character: ţ]]a Universit[[unable to display character: ă]][[unable to display character: ţ]]ii archeological site and compared them to the frequency in a control group from local modern population. This archaeological site is one of the biggest medieval cemeteries from Romania providing the opportunity to sample the same population at different points during the medieval period and beyond.
The comparisons couldn’t reveal strikingly different frequencies of the CCR5-delta 32 allele. Our preliminary results based on 18 aDNA of 150 samples and 74 of 2500 modern DNA indicate that the frequency of the allele in medieval Romanian population is not statistically significant when compared to contemporary one suggesting that lethal epidemics had little effect on its present day frequency. We can conclude based on preliminary data that increase in the allelic frequency of the mutant CCR5-delta 32 allele has been positive selected before the medieval centuries.