β^S globin gene haplotype and the stroke risk among Egyptian children with sickle cell disease

Sickle cell disease (SCD) is an inherited disease of the beta globin gene. The β^S globin gene haplotypes are Senegal, Benin, Bantu, Cameroon, Arab-Indian and atypical haplotypes. In SCD, stroke is a life-threatening event in both adults and children. In light of paucity of studies on β^S globin gene haplotypes in Egypt, we aimed to determine β^S globin gene haplotypes in children with SCD and study their impact on stroke risk.

Fifty-two SCD patients were included in the study, they were 26 males and 26 females with age range from 3 to 18 years old. The PCR-RFLP technique was used for the determination of β^S globin gene haplotypes. Transcranial Doppler (TCD) was done to identify patients at risk of stroke.

Benin/Benin was the most prevalent haplotype detected in 50% followed by Benin/Bantu in 30.8% of studied patients. TCD study showed that 14/52 (26.9%) patients had abnormally high TCD flow velocities (TCD velocities ≥170 cm/s) and thus considered high stroke risk group, whereas 38/52 (73.1%) patients had TCD flow velocities <170 cm/s and are considered low stroke risk group. Stroke risk was not found to be associated with β^S globin gene haplotype (p = .532).

This study provides a relevant contribution to our understanding of the anthropological and historical background of the population in Egypt where Benin haplotype is the commonest β^S globin gene haplotype and homozygous Benin/Benin is associated with higher stroke risk than other haplotypes.