Molecular Epidemiology and Hematologic Characterization of Thalassemia in Guangdong Province, Southern China

Abstract

Introduction: About 2% of the population in the world are carriers of the thalassemia gene. Thalassemia is highly prevalent in Southern China, and traditional clinical testing methods would cause missed diagnosis of partial static thalassemia. Here, we reviewed and summarized a set of simple and clinically feasible thalassemia detection protocols adopted by the Prenatal Diagnosis and Reproductive Center of our hospital. Methods: From January 1, 2015, to December 31, 2020, 31 512 peripheral blood samples and 3828 prenatal samples were collected in our study. All the peripheral blood samples were performed through thalassemia screening by routine blood tests and hemoglobin electrophoresis and gene detection. The prenatal diagnosis would be implemented for the fetus if the parents were carriers of the same type of thalassemia. Results: A total of 6137 (19.48%) cases were diagnosed as thalassemia, in which 4749 (15.07%) were α-thalassemia, 1196 (3.80%) were β-thalassemia and 192 (0.61%) were co-inheritance of α- and β-thalassemia. For prenatal samples, 3160 (82.55%) cases were diagnosed as thalassemia, in which 2021 (52.80%) were α-thalassemia, 997 (26.05%) were β-thalassemia and 142 (3.71%) were co-inheritance of α- and β-thalassemia. In addition, we also found five novel mutations, including NC_000016.9:g.223681-227492del3812; HBA1: c.301-31_301-24delCTCGGCCCinsG; HBA2: c.95+7C>T for α-thalassemia and HBB: c.263_276delCACTGAGTGAGCTG; HBB: c.315+143G>A for β-thalassemia. Conclusion: The present study updates the epidemiological characteristics and mutation spectrum of thalassemia in Southern China and demonstrated five novel mutations. Our research provides a reference for clinical diagnosis and treatment, prenatal diagnosis, or reproductive genetic counseling for patients with thalassemia in Guangdong.

Enhancing thalassemia gene carrier identification in non‐anemic populations using artificial intelligence erythrocyte morphology analysis and machine learning

“…Our study revealed a high TT prevalence in South China. It is consistent with the literature reported 18 . The high prevalence of TT in South China 1,19 underscores the significance of TT carrier screening in this region 3,6 .…”

“…It is consistent with the literature reported. 18 The high prevalence of TT in South China 1,19 underscores the significance of TT carrier screening in this region. 3,6 The --SEA /αα and α 3.7 /αα genotypes showed the highest proportions in α-TT, while β CD41-42 /β N and β (IVS-II-654) /β N exhibit the highest proportions in β-TT.…”

Molecular Characterization of α‐ and β‐Thalassemia Among Children Less Than 18 Years Old in Guizhou, China

“…The most common gene mutation for the β‐thalassemia was found to be β CD17(A>T) , which is consistent with studies conducted in Yunnan and previous results from Guizhou [ 17 , 24 ]. In Hubei and Fujian [ 2 , 25 , 26 ], the most common mutation associated with β‐thalassemia is β IVS‐II‐654 /β N , whereas in Guangdong [ 27 , 28 ], Guangxi [ 29 ], Sichuan [ 30 ], and Hainan [ 22 ] (Table 4 ), the predominant mutation is β CD41‐42 (‐TCTT) /β N . However, in certain regions, such as Zunyi, Anshun, Qianxinan, and Qiannan, the highest prevalence of the β‐thalassemia genotype is β CD41‐42 (‐TCTT) , possibly due to variations in the distribution of ethnic minorities.…”

Integration of targeted sequencing and pseudo-tetraploid genotyping into clinically assisted decision support for β-thalassemia invasive prenatal diagnosis

“…More than 200 types of β-thalassemia gene mutations have been found at home and abroad, covering the promoter region, exon region, cut region, and 3’ untranslated region of the HBB gene. Epidemiological studies have demonstrated that there are significant geographical and ethnic differences in the types of gene mutations [ 7 , 31 , 32 ]. For example, HBB :c.79G>A carries 50% in India in South Asia, whereas it carries 0.1% in Pakistan [ 33 ].…”

“…A total of 46 β-thalassemia mutations have been reported in the Chinese populations. Eight types, including HBB :c.126_129delCTTT, HBB : c.316-197C>T, HBB : c.216_217insA, HBB : c.52A>T, HBB : c.-78A>G, HBB : c.79G>A, HBB : c.-79A>G, HBB : c.130G>T accounted for more than 95% of the total number of β-thalassemia [ 7 , 31 , 34 ]. On this basis, our group designed a probe capture panel with 12 gene mutation types, including the eight mutations mentioned above, to meet the epidemiological and clinical needs.…”