Marked Microcytosis Research Articles

The haematological effects of glucose-6-phosphate dehydrogenase deficiency and thalassaemia trait: interaction between the two genes at the phenotype level.

Summary:The haematological effects of glucose‐6‐phosphate dehydrogenase (G6PD) deficiency and thalassaemia trait were evaluated in a field study of 317 individuals in an isolated Sardinian village, where both traits were present at high frequency. G6PD deficiency was diagnosed with rigid genetic criteria. Thalassaemia trait was diagnosed on the basis of abnormal osmotic fragility.Complete G6PD deficiency resulted in mild anaemia with macrocytosis, a consequence of mild chronic haemolysis. Partial G6PD deficiency had a similar, but less marked effect. Thalassaemia trait resulted in mild anaemia, with marked microcytosis and moderate hypochromia.The haematological effects of the combination of both traits were equal to the sum of the independent effect of each. The G6PD activity of the individual red cells was similar in thalassaemic and normal individuals. Because of the microcytosis, the G6PD activity per gram of haemoglobin per unit volume of red cells or of whole blood appeared to be elevated in thalassaemia trait.