Haemolytic anaemia with hereditary pyruvate kinase instability developing acute leukaemia

The case of a 27-year-old woman with pancytopenia, revealing acute monocytic leukaemia and haemolytic anaemia, is described in detail. The underlying cause for the red cell destruction was found to be a pyruvate kinase (PK) instability. Further investigation into three generations of her family (n = 12) disclosed a hereditary PK instability. This was proven by performing biochemical studies to elucidate mutants representing a structurally defective enzyme. Since conversions of pancytopenia with acquired red cell enzyme deficiency into leukaemia have been described, our observation emphasizes that hereditary red cell enzymopathy might also be associated with adult acute leukaemia.