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 major complications -painful crisis and presence of infections -were investigated. 100 SCA Tunisian patients and 100 healthy subjects were included in the case control 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.
Fetal hemoglobin (HbF) plays a dominant role in ameliorating morbidity and mortality of hemoglobinopathies. We evaluated the effects of polymorphic markers within the β-globin gene cluster to identify the genetic mechanics that influence HbF on Tunisian sickling patients (n = 242). Haplotype analysis was carried out by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and the framework polymorphism was established by PCR-sequencing, four independent regions of interest were identified: the 5' region of β-LCR-HS2 site, the intervening sequence II (IVSII) region of two fetal (Gγ and Aγ) genes and the 5' region of β-globin gene. The correlation of these various Haplotypes and SNPs with HbF expression and clinical data was studied. Our data showed that among the various polymorphic markers analyzed, only the sequence (AT)xN12(AT)y in LCR HS2 region was significantly associated (p < 0.05) with increased HbF levels, suggesting that the β-globin gene cluster exerts a significant effect on HbF in sickle cell patients. This study can improve understanding of the physiopathology of the disease and aid to increase our ability to predict clinical severity.
β-Globin haplotypes are important to establish the ethnic origin and predict the clinical development of sickle cell disease patients (SCD). To determine the chromosomal background of β S Tunisian sickle cell patients, in this first study in Tunisia, we have explored four polymorphic regions of β-globin cluster on chromosome 11. It is the 5′ region of β-LCR-HS2 site, the intervening sequence II (IVSII) region of two fetal (G γ and A γ) genes and the 5′ region of β-globin gene. The results reveal a high molecular diversity of a microsatellite configuration describing the sequences haplotypes. The linkage disequilibrium analysis showed various haplotype combinations giving 22 “extended haplotypes”. These results confirm the utility of the β-globin haplotypes for population studies and contribute to knowledge of the Tunisian gene pool, as well as establishing the role of genetic markers in physiopathology of SCD.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2025 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.