Genotype distribution and identification of rare variants in α/β-thalassemia in chengdu: including the first report of HBA1:c.300+48C > G

Objective Thalassemia is among the most common inherited diseases worldwide. We aimed to analyze the genotype and frequency distribution of thalassemia in a general hospital in Chengdu and provide a reference for genetic counseling and prenatal diagnosis. Methods A total of 6,357 subjects referred to Xindu District People’s Hospital of Chengdu for thalassemia screening between June 2021 and December 2025 were collected. Thalassemia genotypes were tested using polymerase chain reaction (PCR), flow-through hybridization technology and Sanger sequencing analyses. Results A total of 793 subjects heterozygous or homozygous for alpha/beta-globin mutations were detected from 6,357 blood samples, including 480 α-thalassemia variants, 291 β-thalassemia variants, and 22 cases with concurrent α and β-thalassemia variants. One novel variant, HBA1:c.300 + 48C > G, and was not detected in the IthaGenes, HbVar, dbSNP, Pubmed, and HGMD databases. Conclusion The genotype distribution of thalassemia in a general hospital in Chengdu is complex and heterogeneous. The novel HBA1 variant was identified in a patient with severe anemia; however, its functional impact and clinical significance require further investigation.