Haemoglobin C/alpha thalassaemia: haematological and biosynthetic studies.

A family with genes for haemoglobin C (Hb C) and alpha thalassaemia was studied. The mother had Hb-C trait. The father also had Hb-C trait but in addition displayed microcytosis, elevated Hb-F levels and a concentration of Hb-C less than usual for heterozygotes. The proband was homozygous for Hb-C but had Hb-F levels far exceeding those present in Hb-C disease. Biosynthetic studies of globin synthesis in both father and daughter showed a deficit of alpha chains relative to non-alpha chains, confirming the presence of alpha thalassaemia. The coexistence of alpha thalassaemia influences the level of mutant haemoglobin in haemoglobinopathies in which Hb C is present, in a fashion similar to that observed in sickle-cell trait.