A Common Mutant EcoRI Restriction Endonuclease Site in the 5' Flanking Portion of the Human α -globin Gene

A mutant EcoRI endonuclease restriction site has been identified in 3 of 37 Black subjects and in 2 sibs of one of these persons. This mutation was not encountered in 13 Whites. It is located approximately 6 kilobases "inside" the normal site in the 5' flanking sequence of the alpha-globin chain complex. The shortened alpha-globin gene-bearing segment produced in the EcoRI digest produces a restriction map similar to that observed for the common alpha-globin gene deletion observed in the Black population. However, the restriction map with BamHI is normal, confirming that all four alpha loci are present.