Abstract
Study of the Hpa I polymorphism 3' to the β-globin gene in the Greek population revealed absence of the site in 238 βS chromosomes, in contrast to a much larger sample of chromosomes carrying the βA gene, where this site was consistently positive. Subsequent haplotype analysis of the β-globin gene cluster in 82 βS chromosomes demonstrated that 79 (96%) belonged to haplotype #19, while the three exceptions (all Hpa I negative) could be explained by a δ-β recombination event. Haplotype #19 was never encountered in a parallel study of the 83 βA chromosomes. Comparison of the above results with similar surveys in other parts of the world and consideration of various historical events suggest that the βS mutation was introduced into Greece over the last few centuries by the Saracen raids and/or by settlements of North African slaves brought in by the Arabs, Franks, Venetians, or Ottoman Turks, who have occupied the country over the last millennium.