The British Form of Hereditary Persistence of Fetal Hemoglobin Results From a Single Base Mutation Adjacent to an SI Hypersensitive Site 5′ to the Aγ Globin Gene

The Gγand Aγgenes of an individual homozygous for the British form of Aγnondeletion hereditary persistence of fetal hemoglobin have been cloned and partially sequenced. The Gγgene was normal, but the Aγgene was found to have a single base change (T →* C) at –198 bp relative to the cap site. Supercoiled plasmids containing normal γ-genes or the mutant Aγ-gene displayed an S1-hypersensitive site immediately 5′ to the base change.