Association of XmnI Polymorphism with Fetal Hemoglobin Level in Sudanese Patients with Sickle Cell Disease

Abstract

Background: Sickle cell disease (SCD) is an inherited blood disorder that affects red blood cells. The study
of various modulating factors, and genetic factors affecting the clinical severity of the SCD is an interesting
research focus especially in communities with a distinct genetic background. The XmnI polymorphism is
a common genetic variation that was reported in previous studies to increase fetal hemoglobin (HbF) level.
This was a descriptive cross-sectional study, conducted in El-Obeid city in Northern Kordofan state, western
Sudan, during the period from August to November 2016. The Xmn1 polymorphic site was determined by
polymerase chain reaction. Data was analyzed using SPSS software program version 20. P-value of 0.05
and below was considered of significance. In present study HbF level among normal individuals AA , shown
significant difference (p<0.05) between presence of Xmnl +/+ and absence of Xmnl -/- site. in patients with
SS , the HbF level was higher in those who had one or two Xmnl sites as compared to those with the site
absent . In patients with sickle cell trait AS and AA, only the presence of the one and two Xmnl site (+/+)
compared to the absence of the site (-/-) was associated with significant increase in the HbF level. There is
a close link between the Xmn1 polymorphism site and HbF level. A wide range of HbF level was obtained
both in the present and absence of this site. Further studies with a large sample size as well as analysis BS
haplotypes among the patient with sickle cell anemia population are needed for better understand of possible
association .