Distribution of the CCR5 ∆32 mutation in population groups in Romania

Abstract

Introduction: The CCR5 gene encodes a chemokine receptor used by HIV-1 to gain entry into CD4+ T cells. The CCR5 ∆32 mutation is a 32 base pair deletion that confers resistance against HIV-1 by introducing a premature stop codon and thus abolishing the receptor. The allelic frequency of this mutation in European populations is on average 10%, while in Indian groups the average frequency is 1%. Methods: By means of molecular genetics techniques, respectively PCR-Simplex (Polymerase Chain Reaction-Simplex), we investigated the genotype and allelic distribution of the CCR5 ∆32 mutation in two study groups from Romania, one consisting of 166 Romanian healthy individuals and the other of 133 healthy Roma ethnics. Results: In the Romanian population group we found 144 wild-type homozygous subjects, 21 heterozygous subjects and one subject which was homozygous for the A32 allele, while in the Roma ethnic group 111 subjects were wild-type homozygous and 22 heterozygous. The observed allele frequencies for the ∆32 mutation in the two study groups were 7% in the Romanian population group, respectively 8.3% in the Roma ethnics. Conclusions: This is the first study performed on populations groups from Romania concerning the distribution of the CCR5 ∆32 mutation. At the present moment there is not a single clear explanation to why such a high frequency of the CCR5 ∆32 mutation is found in Roma ethnics and while genetic drift, population mixture, or a specific founder effect can explain in part this required to elucidate the matter.