Elevated haemoglobin F in juvenile and adult chronic myelogenous leukaemia.

Fetal haemoglobin (Hb F) and its G gamma-globin chain contents were examined in 2 juvenile (JCML) and 9 adult chronic myelogenous leukaemia (ACML) patients. One JCML patient's %Hb F was 28.0% and its %G gamma was 41.8%, while another JCML patient's %Hb F was 58.0% and its %G gamma was 65.6%. Four ACML patients gamma-globin gene arrangements in all cases were normal. The presence of the Xmn I site 5' to the G gamma-globin gene (at-158 base pairs from the G gamma-globin gene cap site) was observed only in 1 typical JCML patient with elevated %G gamma. The subhaplotype 5' to the delta-globin gene in 5 ACML patients was [+----], and the other 4 were suspected to be heterozygotes for [+----] and [-++-+]. The frequency of the A gamma T-globin gene in ACML patients may be higher than in the normal Japanese population.