British type alpha 0-thalassaemia in New Zealand.

Alpha zero-thalassaemia of the British type is described for the first time in a New Zealand family. Microcytic, hypochromic red blood cells were found in affected individuals. Exclusion of iron deficiency and beta-thalassaemia suggested alpha-thalassaemia as a possible cause. This was confirmed by the detection of haemoglobin (Hb) H inclusion bodies. Definitive characterisation of the alpha-thalassaemia defect required DNA mapping which demonstrated the British alpha zero-thalassaemia deletion involving both alpha globin genes. alpha zero-thalassaemia should no longer be considered a disorder affecting individuals of Mediterranean or Asian backgrounds. Anglo-Saxons are also an at risk group. Co-inheritance of this abnormality with a second alpha-thalassaemia defect can lead to Hb H disease or Hb Bart's hydrops fetalis.