Clinical features and genetic diagnosis of β-thalassemia in Huizhou

ZHONG Ze-yan; CHEN Jian-hong; GUAN Zhi-yang; HE Hai-lin; ZHONG Guo-xing; YANG Kun-xiang

doi:10.13820/j.cnki.gdyx.20180364

Abstract：Objective To investigate the gene frequency and clinical features of β-thalassemia in Huizhou, so as to provide better guidance for genenetic and prenatal diagnosis. Methods A total of 19585 couples receiving pre-pregnancy and pregnancy examination in Huizhou were selected. Thalassemia screening was conducted by blood routine and hemoglobin electrophoresis, and further genetic diagnosis were conducted among the positive cases. The suspected β-thalassemia samples were processed by Gap-PCR. Results SEA-HPFH tpye, Chinese Gγ (Aγδβ) 0 type and Taiwan type were revealed in 62, 41 and 2 cases among 364 samples, respectively. The total detection rate was 0.27％. The blood routine results of β-thalassemia carriers showed microcytic hypochromic anemia, but with mild or no symptoms of anemia. Hemoglobin analysis showed significant increase in HbF in SEA-HPFH and Chinese Gγ (Aγδβ) 0 thalassemia carriers, in which HbA2 were increased in most of the former while not increased in the latter. Hb F was not significantly increased but only HbA2 increased in Taiwan type thalassemia carriers. Statistical differences were found in hematological phenotype indexes, including MCV, MCH, Hb A, Hb A2 and Hb F between the SEA-HPFH and Chinese Gγ (Aγδβ) 0 heterozygous (P＜0.05). Conclusion There is a high prevalence of β-thalassemia in Huizhou. Microcytic hypochromic anemia and increased HbF are common symptoms. Therefore, the prenatal diagnosis of β-thalassemia is critical to prevent the birth of children with moderate or severe disease.