Identification of a Novel 7-bp Deletion in the α-Globin Gene Cluster in One Chinese Family

Abstract

Deletional α-thalassemia is characterized by reduced hemoglobin A₂ and involves the deletion of a few nucleotides, which is a rare hereditary disease. However, the detection of rare mutations using commonly used genetic tests is highly challenging. In the present study, next-generation sequencing (NGS) was used to identify a novel 7-bp deletion α-thalassemia in one individual from a Chinese family. Hematological parameters of the family members were determined using an automated cell counter, and hemoglobin electrophoresis was performed using a capillary electrophoresis system. Subsequently, NGS was performed on the genomic DNA of the patient and her family members. The 7-bp deletion (named Hb Honghe [HBA1: c.401_407delGCACCGT]) of α-thalassemia in the α-globin gene was confirmed using Sanger sequencing. The patient’s father was also a heterozygous carrier of HBA1: c.401_407delGCACCGT deletion, but not her mother or sister. The application of the combined molecular approach is essential for the accurate diagnosis of rare thalassemia. This study reports a novel case of α- thalassemia. The characterization of the mutation might provide new insights into genetic counseling and accurate diagnosis of thalassemia.

Keywords:

• α-thalassemia
• next-generation sequencing
• Chinese family
• deletion mutation
• α-globin gene cluster

Acknowledgements

The authors are grateful to the medical technicians and nurses of the department of medical genetics for their help and assistance.

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.

Additional information

Funding

This study was supported by the National Natural Science Foundation of China (81860040, 82160319); Young and middle-aged academic and technical leaders of Yunnan Province (202105AC160034); Famous doctor project of “ten thousand people plan” of Yunnan Province (KH-SWR-MY-2020–011); and Open project of Yunnan clinical medical center (2020LCZXKF-XY03).