Spectrum of thalassemia mutations in fetuses of Han and Li ethinicities in Hainan province, China

Objective: To analyze the frequency and spectrum of thalassemia mutations in amniotic fluid samples collected from Han and Li people in Hainan province of China. Methods: We carried out a retrospective analysis on prenatal diagnosis of amniotic fluid samples collected from pregnant women who may have next generation with high risks of medium or severe thalassemia between 2005 and 2016. Diverse fetal thalassemia genotypes and mutated alleles in Han and Li people were analyzed and cmpared. Results: We examined 536 amniotic fluid samples from Han people and 588 from Li people, among which 406 Han and 500 Li samples were found to carry at least one thalassemia gene mutation, with a detection rate of 75.75% and 85.03%, respectively. Among all α- and β-thalassemia mutant alleles detected, the most frequently found mutations in Han and Li samples were SEA-type of α-thalassemia and 41/42 (–CTTT) of β-thalassemia, respectively. A total of 75 severe thalassemia cases were identified in Han samples and 53 in Li samples. In most of these severe cases, parents chose to terminate pregnancy after being informed of thalassemia-related risks. Conclusions: The thalassemia mutations shows ethnic and area specificity, and that prenatal diagnosis for high-risk thalassemia carrier pregnant women is an efficient approach to prevent and control the occurrence of severe thalassemia in the high-prevalence areas.