Molecular analysis of the beta-globin gene cluster haplotypes in a Sudanese population with sickle cell anaemia

Introduction: Sudan has a multiethnic population with a high frequency of Hb S, but little is known about the β(S) haplotypes in this population. Methods: Blood samples from Sudanese Hb SS individuals were taken at two locations. Family history, age, ethnicity and clinical symptoms were recorded for each subject. Hb S was investigated using cellulose acetate electrophoresis (CAE) and cation exchange-high performance liquid chromatography. Dried blood samples from 93 individuals were used for β(S) haplotype identification based on restriction fragment length polymorphism analysis for seven restriction sites. Results: Haplotypes could be assigned unequivocally to 143 chromosomes. Four of the five typical β(S) -globin haplotypes were identified. The most frequent was the Cameroon (35.0%), followed by the Benin (29.4%), the Senegal (18.2%) and the Bantu (2.8%). The Indian-Arab haplotype was not observed. Three atypical haplotypes were identified in 17 patients, occurring at a combined frequency of 14.6%. One of these, found at the high frequency of 11.8%, possibly represented a new Sudan haplotype. Conclusion: β(S) Haplotyes were demonstrated successfully from dried blood samples. A new haplotype is apparent in Sudan, in addition to the four African haplotypes.