THE AUSTRALIAN TYPE OF NONDELETIONAL (G)GAMMA-HPFH HAS A C-]G SUBSTITUTION AT NUCLEOTIDE-114 OF THE (G)GAMMA GENE

Nondeletional hereditary persistence of fetal haemoglobin (HPFH) resul ts in the continued production of 2-25% haemoglobin F (Hb Fl in the ad ult who is heterozygous for this mutation. This increase is associated with single-base mutations in the promoter region of either the (G) g amma- or (A) gamma-globin genes. Affected positions include -202, -175 , -161, -158 and -114 of the (G) gamma gene, and -202, -198, -196, -19 5, -175, and -117 of the (A) gamma gene. There is now evidence that th ese mutations produce their effect by changing the binding of certain regulatory proteins. We describe a novel C-->G transversion at positio n -114 of the (G) gamma gene which is associated with the phenotype of (G) gamma-HPFH.