[Analysis of Thalassemia Gene Carriers in 19 482 Pregnant Women from 2015 to 2019 in Guilin, Guangxi]

Abstract

Objective: To investigate the types and frequencies of thalassemia genes carried by the pregnant women in Guilin, Guangxi Zhuang Autonomous Region, China.

Methods: From January 2015 to December 2019, blood samples of the pregnant women who visited the Outpatients of Obstetrics clinic and Eugenics Genetic clinic in Affiliated Hospital of Guilin Medical University were collected. Gap-PCR was used to detect deletional α-thalassemia, PCR-RDB to detect the gene mutations of non-deletional α-thalassemia and β-thalassemia, and MLPA or DNA sequencing to detect rare thalassemia mutations. Different types and frequencies of thalassemia mutations carried by pregnant women were analyzed statistically.

Results: A total of 19 482 blood samples were collected, including 3 801 thalassemia gene carriers (19.51%). Seven types of α-thalassemia gene mutation were detected with a carrier rate of 15.43%. Among them, --^SEA deletion (7.32%), -α^3.7 deletion (3.97%), and -α^4.2 deletion (1.4%) were the commonest types. Twelve types of β-thalassemia mutations were detected with a carrier rate of 5.02%. Among them, CD41-42 (-TCTT) (2.32%), CD17 (AAG>TAG) (1.23%), and IVS-II-654 (C>T) (0.55%) were the commonest types. In addition, 107 cases of rare thalassemia gene mutations and abnormal hemoglobin were found at the same time.

Conclusion: Guilin is a high-risk area for thalassemia. Alpha-thalassemia is dominated by --^SEA deletion, -α^3.7 deletion, and -α^4.2 deletion, while β-thalassemia is by CD41-42 (-TCTT), CD17(AAG>TAG), and IVS-II-654(C>T).