Occurrence of hereditary spherocytosis and beta thalassaemia in the same family: globin chain synthesis and visco diffractometric studies.

Hereditary spherocytosis and beta thalassaemia are rarely inherited together. We have studied a large family of Caucasian extraction in whom these two diseases segregate independently over four generations. The diagnosis rested on specialized laboratory findings and in a number of subjects on the measurement of alpha and beta globin chain synthesis. In addition, a viscometric method (osmotic gradient ektacytometry) was used to evaluate the rheological function of the erythrocytes. In patients inheriting both diseases, the results indicate that the clinical and biological expression of hereditary spherocytosis is modulated by the degree of imbalanced globin chain synthesis. The opposite properties of spherocytes (decreased surface/volume ratio, increased haemoglobin concentration) and thalassaemic red cells (increased surface/volume ratio, decreased haemoglobin concentration) may explain the antagonistic influence of each genotype.