Sequence analysis of Epstein–Barr virus BALF2 gene in associated tumors and healthy individuals from southern and northern China

Aim: The purpose of this study is to investigate the polymorphism and distribution characteristics of BALF2 gene in Epstein–Barr virus (EBV)-associated tumors (gastric cancer, nasopharyngeal carcinoma and lymphoma). Materials & methods: DNA sequences of 349 EBV-related samples were analyzed by nested PCR combined with DNA sequencing. Results: According to the phylogenetic tree, BALF2 was divided into six genotypes ( BALF2-A–F). Statistically, the incidence of BALF2-E in nasopharyngeal carcinoma was higher than that in healthy people, and the incidence of BALF2-E in nasopharyngeal carcinoma in South China was higher than that in North China (p = 0.001). Conclusion: BALF2 variants in EBV-associated samples are not only tumor-specific, but also differ between northern and southern regions.