Deletion of the β-globin structure gene in hereditary persistence of foetal haemoglobin

HEREDITARY persistence of foetal haemoglobin (HPFH) is a condition characterised by the persistence of a high percentage of foetal haemoglobin into adulthood¹. The homozygous state has been described in the Negro^2-4 and the Indian⁵; only haemoglobin F is present, and haemoglobins A and A₂ are absent. It has been suggested that in this syndrome γ-chain synthesis fails to switch to β-chain synthesis after birth. The reason for this failure is unknown, although deletions of the β- and δ-structural genes have been proposed⁶. We report here analysis of the DNA from a patient with the homozygous form of HPFH, using radioactive DNAs complementary to β- and γ-globin mRNA (β and γcDNAs); the results are compatible with deletion of the β-globin structural locus.