Restriction endonuclease maps of the β-like globin gene cluster in the British and Greek forms of HPFH, and for one example ofGγβ+HPFH

Abstract
Restriction endonuclease maps of the .beta.-like globin gene cluster for the British form of HPFH [hereditary persistence of fetal Hb] and a case of G.gamma..beta.+ HPFH are reported, and previous reports of the map for the Greek form of HPFH are confirmed and extended. All these conditions belong to a group lacking any substantial deletion or rearrangement of DNA sequence in this gene cluster. The absence of any gross disruption of the structure of this region of the genome, together with evidence that the HPFH genotype is either allelic with, or closely linked to, the .beta.-like globin gene cluster, suggests that the responsible lesions are nearer to being purely regulatory in nature than in forms of HPFH due to substantial deletions. These conditions promise to provide less equivocal evidence about the regulation of .beta.-like globin gene expression than has so far been available.