title: Population structure of Sicily: beta-thalassemia and HbS.
abstract: The population structure of two alleles with similar characteristics, HbS and beta-thalassemia, was studied in the same area in Sicily. It was observed that beta-thalassemia has uniform frequencies over the island, and that HbS shows a South-North cline. A singularity exists for HbS in the town of Butera, where the frequency of the S gene is six times higher than the island average. It was suggested that HbS entered Sicily from Greece (or directly from North Africa) when the beta-thalassemia allele was already established in the Island.
mesh_terms: D000483:Alleles; D000755:Anemia, Sickle Cell / Q000235:genetics*; D005787:Gene Frequency; D006801:Humans; D012802:Sicily; D013789:Thalassemia / Q000235:genetics*