Prevalence and genetic analysis of thalassemia in childbearing age population of Hainan, The Free Trade Island in Southern China

Abstract

Background: Hainan has one of the high incidences of thalassemia in China, but the epidemiological data in the whole province has not been reported yet. The objective of our study was to reveal the true prevalence and molecular mutation spectrum of thalassemia in the population of Hainan who are of childbearing age.

Methods: We screened 166,936 individuals from 19 cities and counties in Hainan by hematological parameters analysis, and further conducted genetic analysis for individuals whose MCV was less than 82fL.

Results: In total, 21,619 (12.95%) subjects were diagnosed as thalassemia carriers or patients. The overall prevalence of α-thalassemia, β-thalassemia, and α+β-thalassemia were 10.39%, 1.38%, and 1.18%, respectively. Eleven α-thalassemia mutations and sixteen β-thalassemia mutations were identified. The high-frequent genotypes of α-thalassemia were -α^3.7 /αα (19.70%), -α^4.2 /αα (19.39%), αα/--^SEA (15.60%), α^WS α/αα (9.24%), and -α^3.7 /-α^4.2 (8.90%), and those of β-thalassemia were β^{CD41/42(-TTCT)} /β^N (58.92%), β^-28(A>G) /β^N (16.05%), β^{IVS-Ⅱ-654(C>T)} /β^N (8.42%), β^CD71/72(+A) /β^N (6.03%), β^CD17(A>T) /β^N (5.47%), and β^{CD26 (GAG>AAG)} /β^N (2.69%). In addition, the frequencies and hematological profiles of many rare mutations of α- [Fusion, HKαα, αααanti^4.2 , IVS-II-55 (T>G), IVS-II-119 (-G,+CTCGGCCC)] and β-globin genes [-50 (G>A), IVS-Ⅱ-81 (C>T)] in Hainan were reported for the first time.

Conclusion: Our study revealed the high prevalence and extensive molecular spectrum of thalassemia in childbearing age population of Hainan, suggesting thalassemia in Hainan ranks second in prevalence among all regions in China. The findings will be useful for genetic counseling and prevention of thalassemia.

Keywords: childbearing age; molecular spectrum; prevalence; thalassemia.