Prevalence and molecular spectrum of α- and β-globin gene mutations in Hainan, China.

This study investigated prenatal diagnosis of α-thalassemia and β-thalassemia in 3049 families in 18 regions of Hainan Province. Molecular diagnosis was performed in 3049 couples with thalassemia in Hainan Province. Genomic DNA was extracted from peripheral blood of the couples and villus, amniotic fluid, or cord blood of fetuses. DNA-based diagnosis was performed using polymerase chain reaction. The most commonly detected mutation for α-thalassemia was- SEA/αα (31.53%), followed by - α4.2/αα (11.15%) and - α3.7/αα (11.02%). The most common mutation for β-thalassemia was CD41/42 (30.27%), followed by - 28 (2.56%). Prevalence was highest in the coastal regions and lowest in the Wenchang, Lingao, and Ding'an regions. We also found that the most common gene mutations in Han people and other minority groups were not homogeneous. Prenatal diagnosis showed 556 normal fetuses, 116 with α-thalassemia hydrops, and 134 with β-thalassemia major. Our findings provide important information for clinical genetic counseling regarding prenatal diagnosis for thalassemia major in Hainan Province.