Novel Double Heterozygosity: HBA2: c.70G > A (Hb Chad)/HBB: c.-78A > G and Novel Compound Heterozygosity: HBA2: c.70G > A (Hb Chad)/HBA1: c.84G > T (Hb Hekinan II) Hemoglobinopathy in a Chinese Family.

Abstract

HBA2: c.70G > A (Hb Chad) and HBA1: c.84G > T (Hb Hekinan II) are extremely rare α-globin chain variants, while HBB: c.-78A > G is a relatively common mutation in β-thalassemia. This study aims to identify potential hemoglobin variants in a 12-year-old Chinese boy (proband) and evaluate the presence of thalassemia trait in his parents. We used an automated blood cell analyzer to obtain hematological data, capillary zone electrophoresis to analyze hemoglobin, and sequencing of α-globin and β-globin genes for molecular characterization. The proband exhibited typical thalassemia traits, with hemoglobin electrophoresis suggesting a complex α- and β-chain hemoglobinopathy. Genetic testing revealed that the proband was a double heterozygote for HBA2: c.70G > A (Hb Chad) and HBB: c.-78A > G, while the proband's mother was a compound heterozygote for HBA2: c.70G > A (Hb Chad) and HBA1: c.84G > T (Hb Hekinan II). This study reports for the first time two novel cases of hemoglobinopathy in a Chinese family, involving HBA2: c.70G > A (Hb Chad)/HBB: c.-78A > G and HBA2: c.70G > A (Hb Chad)/HBA1: c.84G > T (Hb Hekinan II).