[Association Analysis between Genotype and Phenotype of α,β-Thalassaemia Carriers in Huizhou Area of Guangdong Province]

Abstract

Objective: To analyze the prevalence, genotype distribution and hematological characteristics of α,β-thalassaemia carriers in Huizhou area of Guangdong Province.

Methods: 10 809 carriers of simple β-thalassaemia and 1 757 carriers of α,β-thalassaemia were enrolled as our study cohort. The hematological parameters were detected by automated blood cell counters and automatic capillary electrophoresis. Suspension array technology, gap-polymerase chain reaction (gap-PCR) and PCR-reverse dot blot were used for the genotyping of thalassaemia carriers.

Results: The prevalence of α,β-thalassaemia in Huizhou area of Guangdong Province was 1.99%. A total of 62 genotypes were detected, and the most prevalent genotype was --^SEA/ αα, β^CD41-42/ β^N (19.29%), the next was --^SEA/ αα, β^IVS-II-654/ β^N (16.73%). Significant differences in mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) were found between different genotype groups for simple β-thalassaemia and α,β-thalassaemia. Violin plots showed that carriers with co-inheritance of β-thalassaemia and mild α-thalassaemia expressed the lightest anemia, and carriers with co-inheritance of β-thalassaemia and hemoglobin H (Hb H) disease expressed the most severe anemia.

Conclusion: There is a high prevalence of α,β-thalassaemia in Huizhou area of Guangdong Province. Because of the lack of specific hematological makers for diagnosis of α,β-thalassaemia, it is necessary to distinguish it from simple β-thalassaemia by genotyping of α- and β-thalassaemia in order to correctly guide genetic counseling and prenatal disgnosis.

Keywords: Huizhou area; genotype; hematological characteristics; α,β-thalassaemia.