Haptoglobin Gene Polymorphisms in Sickle Cell Disease Patients with Different βS-Globin Gene Haplotypes
Objective: To investigate the prevalence of haptoglobin (Hp) gene alleles in Kuwaiti sickle cell disease (SCD) patients, who generally have a mild phenotype, and compare the pattern to Nigerian SCD patients whose SCD phenotype is more severe. Subjects and Methods: Hp genotyping was carried out in a group of 82 and 54 SCD patients from Kuwait and Nigeria, respectively, and appropriate Hb AA controls. The Hp genotyping was done using a PCR technique followed by agarose gel electrophoresis. Results: The frequency of the Hp-2 allele was 73.8% among Kuwaiti SCD patients, while the Hp-1 allele predominated among Nigerian patients (60.7%). However, the differences were not significant (p > 0.05) when the allele distributions were compared between Kuwaiti SCD and their AA counterparts or between Nigerian SCD and their AA controls. There was no association of Hp-2 allele with frequent vaso-occlusive crisis among the Kuwaiti SCD patients. Conclusion: The distribution of Hp alleles appears to follow ethnic and geographical trends. Their role in the pathophysiology of pain crisis is not clear.