Beta thalassemia minor (one gene mutation or deletion). This condition results in a range in beta chain synthesis from 10–50%.
Beta thalassemia minor exists in several states and is identified with plus or zero, as noted earlier in the course. These notations correlate with the degree of gene deletion or inactivation.
Because the delta gene is located near the beta gene, it is included in the beta thalassemia classification.
The following pages include illustrations of beta thalassemia states.