The γ(G)-158 (C→T) polymorphism plays important function in the disease severity of sickle cell anemia. The XmnI restriction site at -158 position of the γ(G)-gene is associated with increased expression of the γ(G)-globin gene and higher production of HbF. This study aims to determine the frequency of the different genotypes of the γ(G) Xmn I polymorphism in sickle cell anemia and sickle cell trait patients in Chhattisgarh and its association with high HbF level. The Xmn1 polymorphic site was determined by PCR-RFLP procedure. XmnI polymorphism were studied in 100 sickle cell patients (SS), 50 sickle cell trait (AS) and 50 controls individuals (AA). The presence of XmnI (+/+) site in SS and AS patients associated with the increase of HbF (P<0.0001) synthesis. we also find that presence of one XmnI (+/-) site in SS patients compared with XmnI-/- site had not shows difference in HbF level. Polymorphic association is found between presence and absence of XmnI site with HbF level, in AS and AA individuals.
Keywords: HbF level; globin polymorphism; sickle cell anemia.