[Analysis of hematological characteristics of patients with three common deletional β-thalassemias and concomitant α-thalassemia in Huizhou, Guangdong province].

Objective: To analyze the hematological characteristics of patients with three common deletional β-thalassemia and concomitant α-thalassemia in Huizhou, Guangdong province.

Methods: A total of 1 335 subjects of childbearing age with hemoglobin F (Hb F) ≥ 5% at the Huizhou First Maternal and Child Health Care Hospital between June 2014 and December 2023 were enrolled as our study cohort. The hematological parameters were determined by blood cell counters and automatic capillary electrophoresis, while liquid phase chip and gap-PCR were employed for the detection of routine thalassemias and the three common deletional β-thalassemia, respectively. The hematological characteristics of patients with the deletional β-thalassemia were analyzed. This study was reviewed and approved by the Ethics Committee of Huizhou First Maternal and Child Health Care Hospital [Ethics No. 20231107(B2)].

Results: A total of 384 cases of the three common deletional β-thalassemia were identified, including 184 cases of Chinese Gγ⁺(Aγδβ)⁰, 191 cases of Southeast Asian hereditary persistence of fetal hemoglobin (SEA-HPFH), and nine cases of Chinese Taiwanese, for a total detection rate of 28.76%. Patients who did not meet the established criteria were excluded from the study, leaving 372 cases. All of which presented with hypochromic microcytic anemia and significantly elevated Hb F. Except for normal or decreasing of Hb A2 levels in patients with Chinese Gγ⁺(Aγδβ)⁰, the levels of Hb A2 in patients with the other two deletional β-thalassemia were increased with different degrees. Differential comparison results showed that significant differences were observed in Hb A2 and Hb F values among the groups of the three common deletional β-thalassemia heterozygotes (P < 0.05). According to the type of gene variation, 180 patients with Chinese Gγ⁺(Aγδβ)⁰ heterozygotes were divided into three groups, including αα/αα, Chinese Gγ⁺(Aγδβ)⁰/β^N (149), -α/αα, Chinese Gγ⁺(Aγδβ)⁰/β^N (14), and --/αα, Chinese Gγ⁺(Aγδβ)⁰/β^N (17). Similarly, 179 patients with SEA-HPFH heterozygotes were divided into three groups, including αα/αα, SEA-HPFH/β^N (150), -α/αα, SEA-HPFH/β^N (12), and --/αα, SEA-HPFH/β^N (17). Differential comparison results showed that the Hb F levels of the Chinese Gγ⁺(Aγδβ)⁰ combined with α⁰-thalassemia group were significantly lower than those of the Chinese Gγ⁺(Aγδβ)⁰ combined with α⁺-thalassemia group and the control group (P < 0.05). The mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and Hb F values of the SEA-HPFH combined with α⁰-thalassemia group were significantly lower than those of the SEA-HPFH combined with α⁺-thalassemia group and the control group (P < 0.05).

Conclusion: The above research results can not only enhance the ability of clinicians to identify deletional β-thalassemia and concomitant α-thal, improve the level of genetic counseling, but also provide data support for the development of deletional β-thalassemia prevention and control programme and the development of prenatal and postnatal care.