The gene spectrum of thalassemia in Yangjiang of western Guangdong Province

Hong-Feng Liang; Wei-Min Liang; Wen-Guang Xie; Fen Lin; Li-Li Liu; Lie-Jun Li; Yi-Yuan Ge; Min Lu; Yu-Wei Liao; Guang-Kuan Zeng; Jin-Xiu Yao; Jing-Wei Situ; Li-Ye Yang

doi:10.3389/fgene.2023.1126099

The gene spectrum of thalassemia in Yangjiang of western Guangdong Province

Front Genet. 2023 Feb 13:14:1126099. doi: 10.3389/fgene.2023.1126099. eCollection 2023.

Authors

Hong-Feng Liang¹, Wei-Min Liang², Wen-Guang Xie², Fen Lin³, Li-Li Liu¹, Lie-Jun Li⁴, Yi-Yuan Ge⁴, Min Lu⁴, Yu-Wei Liao¹, Guang-Kuan Zeng¹, Jin-Xiu Yao⁵, Jing-Wei Situ⁵, Li-Ye Yang¹

Affiliations

¹ Precision Medical Lab Center, People's Hospital of Yangjiang, Yangjiang, Guangdong, China.
² Medical Laboratory, Women and Children Hospital of Yangjiang, Yangjiang, Guangdong, China.
³ Precision Medical Lab Center, Chaozhou Central Hospital Affiliated to Southern Medical University, Chaozhou, Guangdong, China.
⁴ Guangdong Hybribio Limited Corporation, Chaozhou, Guangdong, China.
⁵ Laboratory Medical Center, People's Hospital of Yangjiang, Yangjiang, Guangdong, China.

Abstract

Background: Thalassemia presents a higher incidence in southern China. The objective of this study is to analyze the genotype distribution of thalassemia in Yangjiang, a western city of Guangdong Province in China. Methods: The genotypes of suspected cases with thalassemia were tested by PCR and reverse dot blot (RDB). Unidentified rare thalassemia genotypes of the samples were further ascertained by PCR and direct DNA sequencing. Results: Among 22467 suspected cases with thalassemia, 7658 cases were found with thalassemia genotypes using our PCR-RDB kit. Among these 7658 cases, 5313 cases were found with α-thalassemia (α-thal) alone, --^SEA/αα was the most common genotype, accounting for 61.75% of α-thal genotypes, and the following mutations were found: α^3.7/αα, -α^4.2/αα, α^CSα/αα, α^WSα/αα, and α^QSα/αα. A total of 2032 cases were found with β-thalassemia (β-thal) alone. β^CD41-42/β^N, β^IVS-II-654/β^N, and β^-28/β^N accounted for 80.9% of all β-thal genotypes, and the following genotypes were found: β^CD17/β^N, β^CD71-72/β^N, and β^E/β^N. Compound heterozygotes of β-thal and β-thalassemia homozygotes were identified in 11 and five cases, respectively, in this study. α-thal combined with β-thal was identified in 313 cases, showing 57 genotype combinations of the coincidence of both Hb disorders; one extreme patient had a genotype of --^SEA/α^WSα and β^CD41-42/β^-28. In addition, four rare α-mutations (--^THAI, HKαα, Hb Q-Thailand, and CD31 AGG>AAG) and six rare β-mutations (CD39 CAG>TAG, IVS-Ⅱ-2 (-T), -90(C>T), Chinese ^Gγ⁺(Aγδβ)0, CD104 (-G), and CD19 A>G) were also found in this study population. Conclusion: This study provided detailed genotypes of thalassemia in Yangjiang of western Guangdong Province in China and reflected the complexity of genotypes in this high-prevalence region, and this would be valuable for diagnosis and counseling for thalassemia in this area.

Keywords: China; Guangdong Province; gene testing; genotype; thalassemia.

Grants and funding

This study was supported by the Natural Science Foundation of Guangdong Province (No. 2016A030307035) and High Level Development Plan of People’s Hospital of Yangjiang (Nos G2020007 and 2021007).