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

Sudan has a multiethnic population with a high frequency of Hb S, but little is known about the β(S) haplotypes in this population.

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.

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.

β(S) Haplotyes were demonstrated successfully from dried blood samples. A new haplotype is apparent in Sudan, in addition to the four African haplotypes.