Two Rare Pathogenic HBB Variants in a Patient with β-Thalassemia Intermedia

The β-thalassemias are a group of hereditary disorders with autosomal recessive inheritance characterized by the presence of defective synthesis of the β-globin chain, an integral component of the hemoglobin molecule, resulting in either partial synthesis (β+) or complete absence (β0) [1]. The disease reaches a high frequency in the Mediterranean Basin, Africa, the Middle East, the Indian subcontinent, and Southeast Asia [2]. According to the World Health Organization, the frequency of abnormal hemoglobin is 7% globally [3]. β-Thalassemia major is characterized by completely inhibited synthesis of beta chains [4], and so it must be treated, generally by transfusion therapy [4]. The β-thalassemia major phenotype has homozygotes or compound heterozygotes for β0 or β+ genes.