GENOTYPE-PHENOTYPE CORRELATION OF SICKLE CELL DISEASE IN

We have identified the P“-globin gene haplotypes of 85 patients with sickb cell disease attending the Dubai Thalassemia Center and assessed the influence of haplotype, a-thalassemia, and fetal hemoglobin on the clinical presentation. Identzjication of the p” haplotypes was based on mutation analyses in the promoter sequences of the “y- and Ay-globin genes. The Arabian-Indian haplotype was found in 52 % of the p” chromosomes, whereas the remaining were the Bantu and Benin haplotypes. Those with the Arabian-Indian haplotype in this group had a significantly higher fetal hemoglobin (Hb F) level (mean 27%) and a mih clinical course. In contrast, those with the Afican haplotypes, Bantu and Benin, expressed relatively lower Hb F levels (mean 11.3%), with a severe clinical presentation. Coinhm’tance of a-thalassemia trait in the Afican haplotypes had an ameliorating gfect on hemolytic episodes, but vaseocclusive mses were more frequent.