Analysis of the 5′ flanking sequence of the Gγ globin gene by denaturing gradient gel electrophoresis confirms the heterogeneity of the Bantu βs haplotype

The GC?TT polymorphism recently described at positions — 1106 and — 1105 in the 5' flanking region of the G? globin gene for the Bantu ß^S haplotype was analysed by denaturing gradient gel electrophoresis. We studied 108 ß^S chromosome and 122 ß^A chromosomes. The TT sequence was found as follows: in all of 80 chromosomes bearing the Bantu ß^S haplotype with the 6-bp deletion -400 nt from the G? gene in 3 out of 5 Bantu ß^S chromosomes without the deletion, in 1 out of 122 ß^A chromosomes from different ethnic origins but in none of 23 ß^S chromosomes bearing the Senegal, Benin or Cameroon haplotypes. These results confirm the heterogeneity of the Bantu ß^S haplotype and allow a tentative evolutionary sequence for the different alleles at this locus to be presented.