Raised Foetal Haemoglobin in Childhood Leukaemia

S ummary . Very high (13–50 per cent) concentrations of foetal haemoglobin (Hb F), usually found in the juvenile type of chronic granulocytic leukaemia or erythroleukaemia, were detected in three leukaemic children. One with acute myeloblastic and another with histiomonocytic leukaemia died 2 and 5 years respectively after the onset of an atypical syndrome characterized by frequent infections, lymph‐adenopathy, pulmonary infiltrations, hepatosplenomegaly, skin rash and monocytosis. A third child had acute monomyeloblastic leukaemia. Hb F was increased in 18 (55 per cent) of 32 other children with leukaemia; the levels were far below those found in the patients presented, but significantly greater than control values. The occurrence of such high Hb‐F concentrations in acute myeloblastic, monomyeloblastic and histiomonocytic leukaemia has not been reported previously. A raised Hb F in atypical myelo‐ or reticuloproliferative syndromes may have diagnostic and prognostic significance.