Frequency of three polymorphisms of the CCL5 gene (RS2107538, RS2280788 and RS2280789) and their implications for the phenotypic expression of sickle cell anemia in Tunisia

Abstract

The pro-inflammatory context of sickle cell disease promotes the liberation of cytokines such as CCL5, encoded by a gene located on chromosome 17. Herein, the occurrence of three variations of CCL5 in sickle cell anemia (SCA) and their relations to two ma-jor complications - painful crisis and presence of infections - were investigated. 100 SCA Tunisian patients and 100 healthy subjects were included in the case con-trol study. Then the sample of patients was divided into two groups according to the presence or absence of each complication. The polymorphisms, namely g.-403G>A, g.-28C>G and g.In1.+1T>C, were analyzed by PCR/sequencing. Our findings show the presence of eight genotypes, namely GG, GA and AA of g.-403G>A, CC, CG and GG of g.-28C>G, and TT and TC of g.In1.+1T>C. The frequencies of studied single nucleotide polymorphisms (SNPs) and haplotypes in SCA patients do not differ significantly from healthy control group results. There is also no significant association between the analyzed polymorphisms and complications as for painful crisis and presence of infections (p > 0.05). Altogether, our data support the conclusion that the three polymorphisms of CCL5, namely g.-403G>A, g.-28C>G and g.In1.+1T>C, do not seem to be involved in the clinical variability of SCA in Tunisia.