Lineage distribution and E2 sequence variation of high-risk human papillomavirus types isolated from patients with cervical cancer in Sichuan province, China

To explore the nucleotide sequence variability of the E2 gene in high-risk HPV types in cervical cancer patients from Sichuan province, China, the E2 genes of eight high-risk HPV types were amplified and sequenced. Several novel nucleotide substitutions and deletions were observed. The lineages to which the isolates belonged were determined by phylogenetic analysis, employing the sequence of the representative lineages/sublineages in the coherent classification and nomenclature system as references. This study updates the lineage distribution data on high-risk HPV types in Southwest China and helps broaden understanding of the polymorphism of the E2 gene.