RS12574989 and haplotype associated with α/β-chain imbalance and population HbA2 reduction

Determining the associated relationship of genotype and phenomenon would benefit the understanding of disease and renew disease intervention means. 14,518 patients who underwent haemoglobin electrophoresis from June 2020 to December 2020 were enrolled in our study, and additional data including sex, age and routine blood examination results were collected. We focused on individuals with normal red blood cell indices and no common thalassemia pathogenic mutation and selected three groups for the following study: the control group (2.5% ≤ HbA₂ ≤ 3.5%), the HbA₂ under 2.5 group (HbA₂ < 2.5%) and the HbA₂ under 2.4 group (HbA₂ < 2.4%). Four regions of β-globin regulation were sequenced. Statistical analysis was conducted to compare the collected information of the three groups and the genotype distributions in the control group and sequenced group. The HbA₂ under 2.5 group was characterized by a majority of females and lower red blood cell counts and haemoglobin compared with the control group. There were genotypes associated with the grouping as the T of rs12574989 and TTTAGC of the haplotype were significantly increased in the HbA₂ under 2.4 group and CTTAGC was significantly decreased in the HbA₂ under 2.4 group. This study demonstrated that the genotypes of the population associated with HbA₂ were reduced in southern China.