Screening of Some Indicators for Alpha-Thalassemia in Fujian Province of Southern China

Lin Zheng, Hailong Huang, Xiaoqing Wu, Linjuan Su, Qingmei Shen, Meiying Wang, Na Lin, Liangpu Xu Medical Genetic Diagnosis and Therapy Center of Fujian Maternity and Child Health Hospital, Affiliated Hospital of Fujian Medical University, Fujian Key Laboratory for Prenatal Diagnosis and Birth Defect, Fuzhou, Fujian, People’s Republic of ChinaCorrespondence: Liangpu Xu; Xiaoqing WuMedical Genetic Diagnosis and Therapy Center of Fujian Maternity and Child Health Hospital, Affiliated Hospital of Fujian Medical University, Fujian Key Laboratory for Prenatal Diagnosis and Birth Defect, No. 18 Daoshan Road, Gulou District, Fuzhou, 350001, Fujian, People’s Republic of ChinaTel +86-13859000585; +86-18650789891Email xiliangpu@fjmu.edu.cn; wuxiaoqing013@126.comBackground: Carrier screening is the most effective means of controlling the prevalence of alpha-thalassemia. However, due to the differences in ethnic populations and genotypes, the distribution of mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) and hemoglobin A2 (HbA2) varies in different regions. This study aimed to examine screening efficiency of these indicators in different genotypes of alpha-thalassemia in Fujian Province, China.Methods: The data of 13,294 subjects collected from May 2016 to December 2019 were reviewed. The participants were categorized as alpha-thalassemia group and negative-for-alpha-thalassemia group based on the results of the genetic analysis. The distribution of MCV, MCH, and HbA2 in different groups was analysed statistically. And the screening efficiency of different indicators and schemes was compared in different genotypes. The positive criteria of MCV < 80fL, MCH < 27pg, and Hb A2< 2.5% were applied.Results: Among the 13,294 subjects, 2658 were alpha-thalassemia carriers. The genotypes of –SEA/αα and -α3.7/αα are the most prevalent with 63.9% and 21.9% in Fujian Province, China. There were significant differences in the distribution of the three indicators in different groups. The detection rate of the three indicators combined screening was 92.6%.Conclusion: The distribution of the three indicators overlapped partly between alpha-thalassemia group and negative-for-alpha-thalassemia group. They showed significant differences in the median comparison of seven common genotypes. Combined screening with MCV, MCH and HbA2 improved the detection rate of alpha-thalassemia. The results of this study provide a data basis for clinical laboratories and a reliable reference for clinical consultation.Keywords: mean corpuscular volume, mean corpuscular hemoglobin, hemoglobin A2, alpha-thalassemia, thalassemia screening