Abstract：Objective To identify the β-globin gene sequence of suspected cases of β-thalassemia (“β-thalassemia” for short”), the rare mutation site identified and the clinical phenotype were analyzed. Methods From January 2020 to March 2022, 20 suspected β-thalassemia carriers with hematologic phenotype but no related β-thalassemia gene test results were negative in Guizhou Provincial People’s Hospital. The full length of β-globin gene was amplified by PCR, The amplification products were sequenced bidirectionally by Sanger sequencing technique. The sequencing results were compared with the β-globin gene reference sequence to find out whether there were rare mutations. Results Among 20 Carriers with suspected β-thalassaemia, 15 were found to carry rare β-globin gene mutations, with a total of six mutation types: CD53(-T), CD5(-CT), CD8(-AA), -88(C＞A), Cap+22(G＞A) and -50(G＞A). Except for one case of -50(G＞A) carrier, the other 14 cases showed the clinical phenotype of β-thalassaemia minor. Conclusion Rare β-globin gene analysis in suspected carriers whose phenotypes were not consistent with their genotypes plays an important role in guiding β-thalassemia genetic counseling, prenatal diagnosis and reducing the birth of children with moderate and severe β-thalassaemia. The results of this study broaden the mutation spectrum of β-globin gene in Chinese population and Guizhou region.
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