title: The origin of mutant beta-globin genes in human populations.
abstract: The discovery that mutant beta-globin genes arise on different chromosomal backgrounds has allowed studies of the origin and spread of some of the common haemoglobinopathies. The beta S mutation has a wide geographic distribution and is found on many different haplotypes, suggesting that it has had multiple independent origins. In contrast, the Indian beta 0 deletion thalassaemia has a restricted geographic distribution and is present on a single haplotype, suggesting a single origin. The limited evidence for the beta-thalassaemia mutations indicates that most have had a single origin and have subsequently reached polymorphic frequencies by selection pressure from malaria.
mesh_terms: D000483:Alleles; D002872:Chromosome Deletion; D005796:Genes; D005914:Globins / Q000235:genetics*; D006239:Haplotypes; D006444:Hemoglobin C / Q000235:genetics; D006446:Hemoglobin E / Q000235:genetics; D006451:Hemoglobin, Sickle / Q000235:genetics; D006801:Humans; D009154:Mutation; D013789:Thalassemia / Q000235:genetics
chemical_list: D006451:Hemoglobin, Sickle; D005914:Globins; D006444:Hemoglobin C; D006446:Hemoglobin E