Analysis of 21 cases of rare β-thalassemia CD5(-CT)

Objective To analyze the genotypes and hematological characteristics of individuals carrying the rare β-thalassemia CD5(-CT) (HBB: c.17_18delCT).

Methods Gene sequencing was employed to detect the rare β-thalassemia genotypes, followed by a retrospective analysis of their hematological data.

Results A total of 21 individuals were identified as carriers of the rare β-thalassemia gene CD5(-CT) through DNA sequencing. Among them, there were 10 females and 11 males, ranging in age from 36 days to 38 years, primarily residing in the southwestern region of China (Yunnan and Guizhou). Among these 21 cases, 14 cases had blood routine results. The average mean corpuscular volume (MCV) was (66.16±6.57) fL and the average mean corpuscular hemoglobin (MCH) was (20.30±1.67) pg. For 11 cases with hemoglobin (Hb) electrophoresis results, the average HbA₂ was (5.30±0.40)%. Furthermore, there were 19 simple carriers of β-thalassemia gene CD5(-CT), and two other CD5(-CT) carriers were combined with α2 globin gene IVS Ⅱ-55 T > G (HBA2: c.300+55T > G) variation and a new α1 globin gene CD83 CTG > GTG (HBA1: c.250C > G) variation, respectively.

Conclusion The distribution of rare β -thalassemia gene CD5(-CT) exhibits regional specificity and hematological characteristics consistent with a β⁰-thalassemia phenotype.