Spectrum of α-thalassemia and β-thalassemia mutations in the Guilin Region of southern China

Abstract

Background and aimsThalassemia is one of the most frequent hereditary hemoglobin (Hb) disorders in southern China. Accurate population frequency data are needed for planning the control of thalassemia in the high-risk Guilin, the southern region of China. MethodsAnemia patients (n=11,143) from the Guilin Region of the Guangxi Zhuang Autonomous Region of southern China were analyzed by Gap-PCR, PCR-based reverse dot blot (RDB), and direct sequencing methods. ResultsOf these patients, 4365 (39.17%) were diagnosed with α-thalassemia (α-thal), 2643 (23.72%) with β-thalassemia (β-thal), and 263 (2.36%) as carriers of both α- and β-thal. The diagnosed α-thal anomalies were related to 6 gene mutations and 27 genotypes, with the most common α-thal mutations being —SEA (61.37%), −α3.7 (18.52%), −α4.2 (6.80%), and αCSα (6.64%). The β-thal anomalies were related to 14 gene mutations and 30 genotypes, with the seven most common mutations [CD41–42 (-TTCT) (52.02%), CD17 (A>T) (22.12%), IVS-II-654 (C>T) (11.29%), −28 (A>G) (5.01%), CD71–72 (4.04%), CD26 (2.28%), and −29 (1.83%)] accounting for 98.58% of the β-globin gene mutations. In addition, CD37 (TGG→TAG) and CD 30 (A→G) were two particularly rare dominant β-thal mutations in Chinese populations. ConclusionsOur data suggested that the population in Guilin are at high risk of α- and β-thalassemia. The results of this study will be useful for genetic counseling and the prevention of severe thalassemia in the Guilin Region.