Genetic counselling in beta thalassemia in Ferrara.

The effects of retrospective and prospective genetic counselling were studied in the Ferrara area, where the gene for beta thalassemia has polymorphic frequency. It was found that retrospective genetic counselling may have an effect in influencing the retrospective behaviour of couples who already have a child with Cooley's anemia. If the child is at a late birth order, reproduction may be terminated; if it is at an early birth order, it is continued, so that reproductive compensation takes place. In prospective counselling, given after population screening, it was found that the individuals identified as heterozygotes know, in a large percentage, what their state is and what its possible reproductive consequences are. However, it was found that the effect of such knowledge is not significant in influencing the marriage choice of heterozygotes.