EFFECT OF ALPHA-GENE NUMBERS ON THE EXPRESSION OF BETA-THALASSEMIA-INTERMEDIA, BETA-THALASSEMIA AND (DELTA-BETA)(0)-THALASSEMIA TRAITS

The effects of variations in alpha-gene numbers on phenotypical expres sion of beta-thalassemia are assessed in 11 subjects of 8 families. Th e study indicates that coexistence of alpha-thalassemia (-alpha(3.7)/a lpha alpha) decreases the HbF in IVSI-6 homozygote and in delta beta-t halassemia trait and may ameliorate the disease in beta-thalassemia co mpound heterozygotes associated with one mild and one severe beta-thal assemia mutation. Coexistence of alpha-gene triplication is associated with an increase in HbF Value and may increase the severity of beta-t rait or beta-thalassemia intermedia. The effects of alpha-gene triplic ation on phenotypic expression of beta-thalassemia trait may not be un iformly observed in every subject affected with a similar genotype.