Molecular epidemiological and hematological profile of thalassemia in the Dongguan Region of Guangdong Province, Southern China

Background Thalassemia is a common inherited hematological disease in tropical and subtropical regions. This study aimed to investigate the mutation spectrum of thalassemia in the Dongguan region of southern China and comprehensively analyze hematologic features of thalassemia carriers with various types of globin mutations. Methods A hematological screening including hematological indices such as mean corpuscular volume (MCV), mean corpuscular hemoglobin content (MCH), and mean corpuscular hemoglobin concentration (MCHC) was conducted in 19 442 people from Dongguan region, Guangdong province of China. Then, 4891 suspected thalassemia carriers were further investigated by genetic analysis of combined NGS and gap-PCR. Results Totally, 2319 (11.9%) cases were diagnosed as carriers of thalassemia, of which 1483 cases (7.6%) were alpha-thalassemia, 741 cases (3.8%) were beta-thalassemia, and 95 cases (0.5%) were co-inheritance of alpha- and beta-thalassemia. In alpha-thalassemia carriers, the phenotypic severity increases with the number of nonfunctional alpha-globin genes. The patients with -(SEA)/alpha(WS)alpha genotype have less severe clinical phenotypes than those with other Hb H diseases. As for beta-thalassemia, the MCV and MCH in both beta(0)and beta(+)carriers are markedly reduced. Conclusions This is the first comprehensive molecular epidemiological survey and hematological profiling of thalassemia in Dongguan area. This study will be benefit for genetic counseling in the clinic and may help pediatricians to make a correct diagnosis of different types of thalassemia.