α-Thalassemia caused by a large (62 kb) deletion upstream of the human α globin gene cluster
Hatton CSR., Wilkie AOM., Drysdale HC., Wood WG., Vickers MA., Sharpe J., Ayyub H., Pretorius IM., Buckle VJ., Higgs DR.
We describe a family in which α-thalassemia occurs in association with a deletion of 62 kilobases from a region upstream of the α globin genes. DNA sequence analysis has shown that the transcription units of both α genes downstream of this deletion are normal. Nevertheless, they fail to direct α globin synthesis in an interspecific hybrid containing the abnormal (αα)(RA) chromosome. It seems probable that previously unidentified positive regulatory sequences analogous to those detected in a corresponding position of the human β globin cluster are removed by this deletion.